Everyone knows that Apple mobile devices run iOS. Many people know that iOS is a lightweight version of the desktop Mac OS X. Some guess that Mac OS X is based on the POSIX-compliant Darwin OS, and those who are seriously interested in IT know that Darwin is based on the XNU kernel, which appeared was born as a result of the merger of the Mach microkernel and FreeBSD kernel components. However, all these are bare facts that will not tell us anything about how iOS actually works and how it differs from its desktop counterpart.
Mac OS X
The operating system installed today on all Macs and (in a modified form) on iPads dates back to 1988, which is also known in the IT world for being the year the first beta version of the NeXTSTEP operating system was released. NeXTSTEP itself was the brainchild of the development team of Steve Jobs, who by that time had already left Apple and founded the NeXT company, which began developing computers for educational needs.
At the time of its introduction, NeXTSTEP was a truly advanced operating system that included many technological innovations. The OS was based on a modified Mach microkernel, supplemented with FreeBSD kernel components, including a reference implementation of the networking stack. NeXTSTEP's higher-level components were written using the Objective-C language and provided application developers with a rich object-oriented API. The system was equipped with a developed and very convenient graphical interface (key components of which were preserved in OS X and even iOS) and a powerful development environment, which included, among other things, a visual interface designer known to all modern developers.
After the failure of NeXT and the return of Steve Jobs to Apple in 1997, NeXTSTEP formed the basis of the Rhapsody project, within which development of the successor system to Mac OS 9 began. In 2000, the Darwin open source project was spun off from Rhapsody, the source code of which was published under the APSL license. and already in 2001, OS X 10.0, built on its basis, was born. A few years later, Darwin formed the basis of the operating system for the upcoming smartphone, about which, until 2007, almost nothing was known except rumors.
XNU and Darwin
Conventionally, the OS X / iOS filling can be divided into three logic level: XNU kernel, POSIX compliant layer (plus various system daemons/services) and NeXTSTEP layer implementing the graphics stack, framework and application API. Darwin includes the first two layers and is distributed freely, but only in the version for OS X. The iOS version, ported to the ARM architecture and including some improvements, is completely closed and distributed only as part of the firmware for iDevice (apparently, this protection against porting iOS to other devices).
At its core, Darwin is a “bare” UNIX-like OS, which includes the POSIX API, a shell, a set of commands and services that are minimally required to operate the system in console mode and run UNIX software. In this regard, it is similar to the basic FreeBSD system or a minimal installation of some Arch Linux, which allow you to run UNIX console software, but do not have a graphical shell or everything necessary to run serious graphic applications from GNOME or KDE environments.
A key component of Darwin is the hybrid XNU kernel, which is based, as mentioned above, on the Mach kernel and FreeBSD kernel components such as the process scheduler, networking stack, and virtual file system (VFS layer). Unlike Mach and FreeBSD, the OS X kernel uses its own driver API, called the I/O Kit, which allows drivers to be written in C++ using an object-oriented approach, greatly simplifying development.
iOS uses a slightly modified version of XNU, but due to the fact that the iOS core is closed, it is difficult to say what exactly Apple changed. It is only known that it is compiled with other compiler options and a modified memory manager that takes into account small amounts of RAM in mobile devices Oh. In all other respects, it is the same XNU, which can be found as an encrypted cache (kernel + all drivers/modules) in the /System/Library/Caches/com.apple.kernelcaches/kernelcache directory on the device itself.
Above the kernel in Darwin is the UNIX/BSD layer, which includes a set of standard C libraries (libc, libmatch, libpthread, and so on), as well as command line tools, a set of shells (bash, tcsh and ksh) and daemons such as launchd and a standard SSH server. The latter, by the way, can be activated by editing the file /System/Library/LaunchDaemons/ssh.plist. If, of course, you jailbreak your device.
This is where the open part of the OS called Darwin ends, and a layer of frameworks begins, which form what we are accustomed to consider OS X / iOS.
Frameworks
Darwin implements only the basic part of Mac OS / iOS, which is responsible only for low-level functions (drivers, system startup/shutdown, network management, application isolation, and so on). That part of the system that is visible to the user and applications is not part of it and is implemented in so-called frameworks - sets of libraries and services that are responsible, among other things, for the formation of a graphical environment and a high-level API for third-party and stock applications
INFO
Like many other operating systems, the Mac OS and iOS API is divided into public and private. Third-party applications have access only to the public and greatly reduced API, but jailbreak applications can also use the private one.
In the standard distribution of Mac OS and iOS you can find dozens of different frameworks that are responsible for accessing the most different functions OS - from the implementation of the address book (AddressBook framework) to the OpenGL library (GLKit). A set of basic frameworks for developing graphical applications is combined into the so-called Cocoa API, a kind of metaframework that allows you to access the main features of the OS. In iOS it is called Cocoa Touch and differs from the desktop version in its focus on touch screens.
Not all frameworks are available on both operating systems. Many of them are specific to iOS only. Examples include AssetsLibrary, which is responsible for working with photos and videos, CoreBlueTooth, which allows access to bluetooth, or iAd, designed for output advertisements in applications. Other frameworks exist only on the desktop version of the system, but from time to time Apple ports certain parts of iOS to Mac OS or vice versa, as, for example, happened with the CoreMedia framework, which was initially available only on iOS.
All standard system frameworks can be found in the system directory /System/Library/Frameworks/. Each of them is located in its own directory, called a bundle, which includes resources (images and descriptions of interface elements), C language headers describing the API, as well as a dynamically loaded library (in dylib format) with the implementation of the framework.
One of the interesting features of frameworks is their versioning. One framework can have several different versions at once, so an application developed for outdated versions of the system will continue to work, even despite changes made to new versions of the OS. This is exactly how the mechanism for launching old iOS applications is implemented in iOS 7 and higher. An app developed for iOS 6 will look and function exactly as if it were running on iOS 6.
SpringBoard
At a higher level are applications that are system and installed from the application store. The central place among them is, of course, SpringBoard (only in iOS), which implements the home screen (desktop). It is the one that is launched first after the start of system daemons, loading of frameworks into memory and the start of the display server (aka compositing manager, aka Quartz Compositor), which is responsible for displaying images on the screen.
SpringBoard is the link between the operating system and its user, a graphical interface that allows you to launch applications, switch between them, view notifications and manage some system settings (starting with iOS 7). But it is also a handler for events such as touching the screen or flipping the device. Unlike Mac OS X, which uses various applications and daemon agents to implement interface components (Finder, Dashboard, LaunchPad and others), in iOS almost everything basic capabilities user interface, including the lock screen and curtain, are contained in one SpringBoard.
Unlike other stock iOS applications, which are located in the /Applications directory, SpringBoard, along with the display server, is considered part of the framework and is located in the /System/Library/CoreServices/ directory. To perform many tasks, it uses plugins that are located in /System/Library/SpringBoardPlugins/. Among other things, you can find there, for example, NowPlayingArtLockScreen.lockboundle, which is responsible for displaying information about the song being played on the lock screen, or IncomingCall.serviceboundle, which is responsible for processing an incoming call.
Starting with iOS 6, SpringBoard is divided into two parts: the desktop itself and the BackBoard service, which is responsible for communications with the low-level part of the OS that works with hardware (HAL level). BackBoard is responsible for processing events such as screen touches, keystrokes, accelerometer, position sensor and light sensor, and also manages the launch, pause and termination of applications.
SpringBoard and BackBoard are so important to iOS that if you somehow stop them, the entire system will freeze in place and even the currently running application will not respond to screen touches. This is different from the Android home screen, which is just standard application, which can be stopped, replaced, or even removed from the system (in this case, fully working navigation buttons and a status bar with a “curtain” will remain on the screen).
Applications
At the very top of this pyramid are applications. iOS distinguishes between built-in (stock) highly privileged applications and third-party applications installed from iTunes. Both are stored in the system in the form of bundles, much like those used for frameworks. The only difference is that the application bundle includes slightly different meta-information, and the place of the dynamic library is taken by an executable file in the Mach-O format.
The standard directory for storing stock applications is /Applications/. In iOS it is absolutely static and changes only during system updates; the user cannot access it. Third-party applications installed from iTunes, on the other hand, are stored in the user's home directory /var/mobile/Applications/ within subdirectories of the form 4-2-2-2-4, where two and four are hexadecimal numbers. This is the so-called GUID - a unique identifier that uniquely identifies the application in the system and is also needed to create an isolated sandbox.
Sandbox
In iOS, sandboxes are used to isolate services and applications from the system and from each other. Every third-party application and most system applications run in a sandbox. From a technical point of view, the sandbox is a classic chroot for the UNIX world, reinforced by the TrustedBSD MAC forced access control system (kernel module sandbox.kext), which cuts off applications not only access to files outside the home directory, but also direct access to hardware and many system OS functions.
In general, a sandboxed application is limited in the following capabilities:
- Access to the file system other than its own directory and the user's home directory.
- Access to the Media and Library directories within the home directory, excluding Media/DCIM/, Media/Photos/, Library/AddressBook/, Library/Keyboard/ and Library/Preferences/.
- Access to information about other processes (the application “considers” itself to be the only one in the system).
- Direct access to hardware (only Cocoa API and other frameworks are allowed).
- Restriction on use random access memory(controlled by the Jatsam mechanism).
All these restrictions correspond to the sandbox profile (set of restrictive rules) container and apply to any third-party application. For stock applications, in turn, other restrictions, softer or stricter, may apply. An example is an email client (MobileMail profile), which generally has the same severe limitations as third-party applications, but can access the entire contents of the Library/ directory. The opposite situation is SpringBoard, which has no restrictions at all.
Many system daemons run inside sandboxes, including, for example, AFC, which is designed to work with the file system of a PC device, but limits its “scope” to only the user’s home directory. All available system sandbox profiles are located in the /System/Library/Sandbox/Profiles/* directory and are sets of rules written in the Scheme language. In addition, applications may also include additional sets of rules called entitlement. In essence, these are all the same profiles, but embedded directly into the application binary file (a kind of self-limitation). You can view these rules, for example, like this:
# cat -tv /Applications/MobileSafari.app/MobileSafari | tail -31 | more
The meaning of the existence of all these restrictions is twofold. The first (and main) task that sandbox solves is protection against malicious applications. Coupled with a thorough check of applications published in iTunes and a ban on launching applications that are not signed with a digital key (read: any applications not received from iTunes), this approach gives an excellent result and allows iOS to be at the top of the list of the most virus-protected operating systems.
The second problem is protecting the system from itself and the user. Bugs can exist both in stock Apple software and in the minds of users. Sandbox protects against both. Even if an attacker finds a hole in Safari and tries to exploit it, he will still remain in the sandbox and will not be able to harm the system. And the user will not be able to “break his favorite phone” and will not write angry reviews to Apple. Fortunately, knowledgeable people They can always jailbreak and bypass sandbox protection (in fact, this is the point of jailbreak).
Multitasking
One of the most controversial iOS features- This is the implementation of multitasking. It seems to exist, but on the other hand, it doesn’t exist. Compared to traditional desktop OS and the notorious Android iOS It is not a multitasking operating system in the traditional sense of the word and does not allow applications to run freely in the background. Instead, the OS implements an API that the application can use to perform individual tasks while it is in the background.
This API first appeared in iOS 4 (before that, only stock applications could perform background tasks) and grew as the operating system developed. Today (we are talking about iOS 7) the so-called Background API allows you to do the following:
- play audio;
- make VoIP calls;
- receive information about location changes;
- receive push notifications;
- schedule delayed notifications;
- request additional time to complete work after going into the background;
- exchange data with accessories connected to the device (including Bluetooth);
- receive and send data over the network (starting from iOS 7).
Such restrictions on working in the background are necessary primarily in order to save battery power and avoid interface lags, so familiar to Android users, where applications can do whatever they want in the background. In fact, Apple cares so much about battery conservation that it has even implemented a special mechanism for grouping background app activities and launching them at the right moments, for example, when the smartphone is actively in use, connected to a Wi-Fi network, or connected to a charger.
conclusions
It is worth saying that during its development and subsequent move to mobile devices, NeXTSTEP not only did not lose all its advantages, but also increased them. You can listen for a long time to the tales of Google employees who claim that Android was developed without regard to iOS, but the fact remains that Android borrowed many architectural solutions from iOS. And not because it was easier, but because of their beauty and effectiveness.
Six stages of iOS download
- Boot ROM. After turning on the device, the first to launch is a minimalistic bootloader flashed into the device’s permanent memory. Its task is to perform the initial initialization of the hardware and transfer control to the primary loader LLB. Boot ROM always has factory firmware and cannot be updated.
- Low Level Bootloader (LLB). Next, LLB takes control. This is the primary bootloader, whose task is to find iBoot in the device’s memory, check its integrity and transfer control to it or switch the device to recovery mode if this fails. The LLB code is stored in the device's NAND memory and is updated when a new firmware version is installed. Among other things, it displays the boot logo.
- iBoot. This is the secondary and main loader for iDevice. It includes a file system driver that accesses the contents of NAND memory, finds the kernel, and transfers control to it. iBoot also has a built-in UART driver, with which you can debug the kernel and OS by connecting the device to a COM port or USB port of your computer (using USB cable- UART).
4 Core. Everything is as usual here. The kernel initializes the hardware and then transfers control to the launchd daemon.
5 Launchd. This is the primary process of iOS and Mac OS X, it connects file systems, runs daemons/services (e.g. backupd, configd, locationd), display server, frameworks, and on last stage loading gives control to SpringBoard. On iOS and Mac OS X, launchd is used as a replacement for the standard /bin/init in UNIX, but its functionality is much broader.
6 SpringBoard. Here is the lock screen!
The first four stages in this chain form a chain of trust, implemented by verifying the digital signature of the downloaded component. Digital signature have LLB, iBoot and a kernel, which eliminates the introduction of a hacked bootloader or kernel into the chain, which can be used to load a third-party operating system or jailbreak. The only way to bypass this mechanism is to find a hole in one of the bootloaders and use it to bypass the check. At one time, several such holes were found in Boot ROM (the most famous exploit is limera1n from geohot, relevant for iPhone 1–4), and at the beginning of 2014 in iBoot (hacker iH8sn0w, the exploit was never published).
By holding down the Home button while turning on your iPhone, you can force iBoot to boot into what's called Recovery mode, which allows you to restore your iOS firmware or update it using iTunes. However, the automatic OTA update mechanism uses a different mode called DFU (Device Firmware Upgrade), which is activated at an early boot stage immediately after the Boot ROM and is implemented in two components: iBSS and iBEC. In fact, these are analogues of LLB and iBoot, the ultimate goal of which is not to load the OS, but to put the smartphone into update mode.
Federal Agency for Education of the Russian Federation
State educational institution higher professional education
South Ural State University
Faculty of Instrument Engineering
Department of Information and Measurement Technology
Operating system iOS
By discipline
Computer science
Introduction
Computers have become an integral part of our familiar world. A computer cannot exist without an operating system. The OS ensures absolutely all the operation of the computer, be it a powerful server or a small phone in your pocket. Therefore, the topic of OS is very relevant nowadays and that’s why I chose it. The analysis I conducted will help you see how one of the most popular operating systems, iOS, has developed in our time, as well as compare it with other operating systems.
Figure 1 - iOS logo
1. What is iOS?
iOS (until June 24, 2010 - iPhone OS) is a mobile operating system developed and released by the American company Apple. Unlike Windows Phone and Google Android, it is released only for devices manufactured by Apple. Was released in 2007. Initially for iPhone and iPod touch, later for devices such as iPad and Apple TV.
The entire screen space consists of four components:
Working screen (or Home Screen) - contains 16 icons for various user purposes: mail, calendar, photos, contacts, notes, clock, calculator, camera, settings, App Store, etc.
Dock line. Located at the bottom of the working screen, it consists of four elements.
Spotlight navigation bar with work screens and search - Bottom part screen
The Status Bar - the upper right corner of the screen - displays the network signal strength, EDGE, 3G, Wi-Fi, Bluetooth, battery charge indicator, alarm status, music playback and TTY.
2. History of iOS
Figure 2 - iOS 1 desktop
The first version of the mobile operating system was built on the same Unix kernel as Mac OS X. Apple CEO Steve Jobs, presenting the first iPhone at the presentation, figuratively called the iPhone OS system ported Mac OS to a new smartphone. But from the first minutes of the presentation it became clear that the differences would be colossal. No matter how innovative the iPhone was at the time of its presentation, its functionality is extremely limited. Few functions that are now familiar were implemented in the first version of the operating system:
· main interface · multi-touch gestures · iPod music app · Safari browser · Cards · synchronization with iTunes. Appeared in updates · web apps on home screen · changing the arrangement of icons · keyboard with multi-touch support · iTunes Music Store In other words, even some of the usual functions of regular phones were missing in the first version of the operating system, such as, for example, voice recorder, video recording, downloading your own ringtones, contact search, sending MMS lack of background image in the menu and others. There were basically no apps on the iPhone. Despite this, the user interface, coupled with touch controls via a capacitive screen, was truly revolutionary.
Figure 3 - Basic functions Figure 4 - Windows Mobile 6 on smartphones from 2006-2007, controlled using styluses and a joystick. The advent of iOS set the direction for the development of operating systems for mobile devices. The iOS user interface is based on the concept of direct manipulation using multi-touch gestures. The interface controls consist of sliders, switches, and buttons. It is designed based on OS X and uses the same POSIX-compliant set of core Darwin components. iOS has four abstraction layers: the Core OS layer, the Core Services layer, the Media Layer, and the Cocoa Touch layer. For the current version of the operating system (iOS 7.0.2), 1.4-2 GB of device flash memory is allocated for the system partition and approximately 800 MB of free space (varies depending on the model). As of May 19, 2013, the App Store contains more than 900 thousand iOS applications, which together have been downloaded more than 50 billion times. 3. Advantages of iOS (Compared to Android - the most popular mobile platform) 1 Automatic update platforms The order of things with updating the operating system on Android and iOS turned out completely differently. If it is impossible to say for sure about devices running on Android that they are all updated, then for i-gadgets this percentage reaches almost 100%. If we analyze the entire mass of Android devices, some of them only have access to version 4.0, the rest run on version 2.3, and another quarter have the right to use the latest software. Where does this differentiation come from? <#"justify">For Apple, in this regard, everything is much simpler and more reasonable. 89.2% of devices today are running the latest build of iOS 6. By the way, Microsoft company I decided to take an example from Apple and made a similar OS update system. iOS users have better luck! 3.2 High level security against malware Some people consider this a plus, others a minus - iOS has closed its doors for third-party software today, which cannot be said about Android. Plus, all applications undergo strict control before being released into the App Store. Like any other iOS system, it is not without vulnerabilities, but engineers from Cupertino take care of their consumers and eliminate errors, releasing new builds on time. <#"justify">.3 Own services Apple Dissatisfaction with iTunes, for example, is made only by those who do not understand the main purpose of this service, as well as others. The ease of use of iCloud has long been proven: synchronization of any data on several i-devices, a tool for creating backup files data, using iCloud for backup, etc. is transparent synchronization, Android will not show this for sure. Apple's proprietary software also includes iMessage, FaceTime, Find My iPhone, etc. All this is available by default in iOS devices; in Android you can find something similar, but among third-party software. 3.4 iOS is a priority for software developers The App Store is rich in choice. Android is trying to keep up and is catching up with Apple. However, most programs, applications, and games are initially released and written specifically for Apple devices, so you can always get the release first in the App Store. And the applications here are better optimized for various iOS devices. 5 Accessibility took care of users with disabilities who have problems with vision, hearing, etc. AssistiveTouch, Guided Access, Color Inversion, VoiceOver, support for hearing aids - all this is natively built into iOS; on Android, this can again be found as part of additional applications. Having listed the main advantages of iOS over Android, I would like to draw your attention once again: are some changes in icons or wallpaper on a springboard much more important than safety, comfort and stability? Linking hardware to software. It seems that this feature is a big minus and at the same time a step forward. Applications are created specifically for one device with certain characteristics (iPhone, iPad, including iPod touch). Thus, users rarely encounter hardware glitches and problems such as incompatibility. 6 Performance The operating system has high performance and stability, and this is not a fictitious opinion, but the opinion of society, which was arrived at by studying various forums, reviews from friends, and services like questions and answers. 7 For a long time battery operation Unlike the Android operating system, iOS managed to realize a high percentage of energy savings. Android users feel that their platform is not fully optimized in terms of battery power usage. It is known that when Android work drains the battery very quickly. To manage this process, you need to resort to special tricks, which takes a lot of time. iPhone users know exactly how long their device lasts. There are definitely no charging problems with Apple products. 8 Proper multitasking The iOS platform is distinguished by successfully implemented multitasking. You can minimize and expand the utility without any difficulties. The most important thing is that minimized programs do not affect the operating system and do not drain battery power. Another undeniable advantage is the fact that each active process can be easily closed in a few movements. Convenient work with wireless communication tools. iOS uses Wi-Fi to access the network. Therefore, the device determines without outside help what needs to be turned on. When there is no Wi-Fi nearby, it starts to work mobile technology transmission of information that is disabled in automatic mode, if not used. 3.9 Ease of learning 10 iTunes service increases the effectiveness of protection Apple constantly complains that an iPhone or iPad without the iTunes service is “zero.” Users cannot install any application in the selected folder, since access is simply denied. 1 Activation The first thing new iOS 7 users will notice is the welcome screen. There are no more textures and an overloaded interface, but there is a white background, thin fonts, and an emphasis on information. Apart from its appearance, the initial setup of the device is no different from what it was before: prompts to read the user agreement, enter a wireless network password, enable geolocation services. 2 Home screen It would seem that everything is familiar on the home screen - a grid of icons, folders, a dock for the most necessary programs. But now everything has become much brighter, more minimalistic, and instead of a glass shelf at the bottom of the screen, the icons will be placed on a colorless stripe that blurs the background. The way folders work has changed. Now you can put an unlimited number of applications in blurred windows. There will be more than nine - additional screens will appear inside. It feels like there is a completely different operating system in front of your eyes, albeit with familiar outlines. 3 Search Spotlight search, notorious for its one-second delay before launching, has been banished from the far left screen. Now, to access it, you will have to swipe your finger from top to bottom on any screen. Traditional delay... and he will be at your service. 4.4 Notification Center In iOS 7, the Notification Center lost all functions except displaying notifications. Posts on Twitter and Facebook were removed from it, but the information content of the drop-down curtain was increased. The Center is now divided into three tabs: Today, All and Missed. The first contains information from the calendar and a text weather forecast, the second tab contains application notifications, and the third is dedicated to missed events. Notification synchronization is finally here. Messages closed by a user on one device will be closed on others. 5 Command Center Figure 14 - Command Center The expanded functionality of the Notification Center, as when using popular tweaks from Cydia, did not appear, but they decided to allocate a separate curtain to the long-awaited switches. It can be accessed by swiping from bottom to top. Users can adjust the volume, backlight brightness, control the player, launch the camera, flashlight or stopwatch. There are also wireless connection switches, AirDrop for transferring files between devices, and an orientation lock button. 6 Lock screen The lock screen has lost the usual “Slide to unlock” slider, so now you can swipe your finger anywhere on the screen. This is hinted at by the signature “Unlock” with an arrow, which only shows the direction of movement, but not the specific location for the gesture. Similar to the home screen, swiping up and down will open the Command Center and Notification Center. To switch modes and view news, you no longer need to unlock the device, which is very convenient. 7 Multitasking In iOS 7, the familiar multitasking panel has changed. It now allows you to see thumbnails of running applications, and you need to close them not with a long press and a cross, but with a stroke of your finger. This principle of operation is familiar to users of smartphones running Web OS and Windows Phone. But the changes are not only external - the process of running applications in the background has been significantly redesigned. Now, depending on how often you use apps, they can be silently updated while inactive, so that users have the latest information when they launch. To do this, in the settings you can select which applications can be updated in the background, or turn off this function to save battery power. 8 Settings The settings of the mobile device have changed significantly. But not the logic of the division, but the possibilities. There's now a customizable blocklist that lets you block unwanted callers in the Phone, Messages, and FaceTime apps. Apple has also added new ringtones, alarms, warnings and system sounds, and changed the set of wallpapers for the desktop and lock screen. Settings also allows you to add Flickr and Vimeo accounts. The Siri virtual assistant in iOS 7 received two new voices: male and female. Apple programmers also taught him to perform more actions than before. In addition to the already familiar functions, Siri can now change settings, find and show tweets, and search Wikipedia and Bing. In addition, the appearance of the dialog box has changed - it now displays the history of calls to Siri. Thanks to the updated assistant, interaction with cars has improved. Now Siri can be 95% integrated into the multimedia system and perform various actions without being distracted from the road. For example, make calls, open maps and get directions, turn on music and change tracks. 10 Game controllers iOS 7 will include expanded support for game controllers. It's too early to judge how this will affect developers and accessory manufacturers, but we can say with confidence that this will not go unnoticed. 11 iBeacons Apple engineers still do not want to add an NFC module to the iPhone, but programmers decided to implement support for iBeacons technology. In some ways it even surpasses the “near field”. Using Bluetooth, a smartphone can read information from special beacons and transmit it to applications. 4.12 Expanded gesture support iOS 7 will give you more reasons to use gestures rather than taps. For example, to switch between applications, browser tabs, manage messages in an email client, or view the time when messages were sent. 13 Wi-Fi HotSpot 2.0 Apple mobile devices can now automatically switch between mobile Internet and wireless networks Wi-Fi without authentication. If a mobile operator also has hotspots installed around the city, smartphones and tablets with a SIM card from that operator will prioritize faster Wi-Fi. In this case, users will not even notice how the switching occurs. 14 Corporate functions Apple mobile devices are popular in the corporate segment, so iOS 7 has new features for those who use smartphones and tablets at work. Now it is VPN setup for individual apps, App Store license management, Exchange Notes synchronization, single identity for enterprises. 15 AirDrop 16 Standard applications The App Store now has a Popular Nearby tab, allowing you to see what's trending near you. Children's apps are now divided into several groups depending on their age rating. The App Store now has automatic update installation, update history, and a wish list. Apple has also increased the limit on downloading applications from the store via the mobile Internet to 100 MB. Now it allows you to make audio calls. apple operational productivity mobile Conclusion The topic of operating systems is very broad and almost inexhaustible, because today there is a fairly large number of different operating systems. And having analyzed, researched and compared only part of them, it is impossible to say with great confidence which one is better. Each system has its own advantages, disadvantages and individual capabilities, therefore, each user will be able to determine the best OS for himself. Therefore, you should try to use several operating systems, and only then make the final choice. Time passes quickly and the development of the OS keeps pace with the times. Today, developers have already come close to almost completely integrating all devices on this OS. In addition, operating systems are increasingly tailored to the consumer, and are becoming simpler and more functional.
Today we’ll talk about the heart of the iPhone and I’ll tell you what iOS is. Oddly enough, some people do not know the name of the operating system on the iPhone.
There is nothing wrong with this, because now you are here and can read this material. I will try to briefly present the information that I have.
iOS system - what is it?
Well, I’ll probably start with the fact that as soon as the first iPhone was released in 2007, there was no name for the operating system yet. Considering that it was based on an OS identical to the MacBook, it was called OS X.
I won’t talk about the name for a long time, because it’s already clear that Apple’s trick is to simply add the letter “i” to everything at the beginning. So it turned out to be iOS, and I think it’s no secret to anyone that OS is an Operating System.
Although it is quite possible that it stands for “iPhone Operating System”. Apple gives its users the opportunity to think for themselves.
It doesn't just work on iPhones. It was developed for major mobile devices, and you can also add iPad and iPod here. 
The entire operation of the system is based on the touch screen. There are no styluses, only fingers. The iPad Pro became an exception not long ago, but it has something like a pen and is needed exclusively for drawing.
The main feature is that the system is completely closed. You will not be able to transfer any file to your device. To do this, you will have to do various manipulations and download a special application.
If we talk about applications and games, they can be downloaded from the App Store. There are a lot of them there now and you can find absolutely everything you need.
How to find out which iOS is on an iPhone?
If you are interested in viewing your version of iOS on your iPhone, you can do this in just a couple of seconds. Just follow these steps:
- choose Settings;
- then click on Basic;
- Now About this device;
- opposite the word "Version" we have the current iOS number.
With these simple steps, you can find out the version at any time you need. The first time according to the instructions, and then I think you will remember.
How is iOS different from Android?
I won’t say too much here, I’ll just tell you the most important differences between iOS and Android and how things generally stand at the moment. 
The first thing I would like to note is probably safety. After all, Android devices are most often hacked; placing a virus there is not such a problem.
There are probably several reasons for this. The first is that Play Market checks applications a little worse and you can take into account that people like to install cracked software.
Well, the second thing is that Android is completely open. Everyone studied her up and down. So everyone knows her strengths and weaknesses. 
The second difference can be called ecosystem. After all, before choosing a device, you must understand exactly what services you want to use.
Android has all the analogues for Apple services. Speaking about iCloud, we immediately remember Google Drive. If it's Siri, then OK Google and so on.
Both sides have their pros and cons. But this is an individual matter and it is best for you to consult with users or simply read information on the Internet. 
Further we can call work stability And device support. In principle, today the difference is not as big as it was before.
If you picked up an Android smartphone three years ago and used it, you would probably find a bunch of lags and slowdowns that were incredibly annoying.
Today, of course, sometimes this is also observed, but much less often. What worries you more is that when you buy a device on this OS, how long will it take to update it to the latest versions.
For Apple, this period is usually around four years. While Android is a couple of years old and you can forget about the latest versions.
It is worth considering that each developer has his own shell. Because of this, it is not a fact that you will be able to receive updates immediately after the release of a new version of Android.
So what is iOS? It's simple: it's an operating system for Apple mobile devices. The name is easy to decipher: “OS” is an “Operating System”, and the letter “i” indicates that this platform is intended for i-devices - iPhone, iPad, iPod. Founder Apple Steve Steve Jobs once explained that the “i” in the names of his new inventions symbolizes individuality, information content, the Internet and many other good things starting with the letter “i.”
The iOS operating system is used on Apple smartphones and tablets, as well as on players from the iPod touch series (other models of iOS players do not support). In addition, the Apple TV set-top box (starting from the second generation) runs iOS.
At the end of 2014, the eighth generation of the operating system, iOS 8, was released. Major updates are usually released in the fall, and are received free of charge by all users of supported Apple devices. iOS has a full set of functions required by a modern mobile platform. It has applications for surfing the web, reading mail, listening to music, watching videos, taking photos, etc. Additional programs can be installed from the integrated store Apple App Store, where there are both paid and free apps for any task - from editing office documents to creating interactive postcards, and, of course, games.
Many iOS features are integrated with the OS X operating system for Apple computers and laptops. For example, in iOS 8, you can start writing a letter on your tablet and finish it on your computer.
What opportunities have appeared for iPad and iPhone users?
According to a long-established tradition, along with the release of new generations of iPhone smartphones, Apple also releases a new version of the operating system. iOS systems. The next - 11th - iOS has become, perhaps, the largest update to the appearance of the operating system since the abandonment of skeuomorphism in iOS 7. But in addition to visual innovations, there is a lot of interesting things here in terms of functionality. Let's get acquainted with iOS 11 and evaluate the main innovations!
First of all, it is worth noting that the most important innovations concern tablets, not smartphones. This is also indicated by the advertising slogan: “A big step for iPhone. A giant leap for iPad." But some of the new features are available in both. We'll start with them.
Files app
One of the most common criticisms against iOS is the lack of a file manager. Apple stubbornly does not provide the opportunity to work with files on the device in the same way as we work with them on a computer, that is, sort into folders, transfer from one folder to another, etc. At first glance, the new “Files” application, which has created The announcement of iOS 11, with so much noise, changes this paradigm. Outwardly it really is file manager, which clearly echoes the design of the Finder in macOS.
We see that files and folders can be assigned color tags, as is done in macOS (although they are assigned very inconveniently and unintuitively); We see that files can be shared by sending them by email or transferring them in other ways typical for iOS. You can even move them into folders.
But please note: there is no access to files on the iPad itself - only in cloud services! In this case, Dropbox and iCloud Drive are connected, on the Apple website we can see in the screenshots Box, Microsoft OneDrive, Google Drive... True, On My iPad is also there, but we were unable to find this item on our tablet. Perhaps this will appear in the final version of iOS 11, but for now the Files application is rather a single hub for managing the content of cloud services.
Note that everything said is also true for the iPhone. In both iPhone and iPad, after updating, the “Files” icon automatically appears among the applications.
Command centre
The Control Center has changed significantly - a translucent screen that can be opened with a gesture from the bottom of the screen. Now you can change the set of widgets and their location. All this is done through Settings / Control Center.
In the case of the iPad this is less useful, but for the iPhone this feature is a real godsend. The screenshots below show that voice recorder and notes icons have been added, but the timer has been removed.
Another useful innovation available on both iPhone and iPad is the notification feed, accessible directly from the lock screen. And only on iPhone - a new car mode. When the smartphone is in this mode, no notifications are received, and when trying to contact the subscriber, a message is received stating that the person is driving.
Interestingly, this mode can be activated either manually or automatically if the smartphone detects that a person is in motion. True, in this case it will also turn on on a bus, for example, or in a taxi. So there is a third, optimal option: automatic activation when connected to the car’s Bluetooth.
Updated App Store interface
One of the most controversial innovations is the App Store interface. Apple has radically redesigned it (for both the iPhone and iPad), and frankly, we can't say it's any better. It turned out to be less informative (in terms of the amount of information per unit of screen area) and more noisy.
In the new App Store, the emphasis has shifted specifically to the choice of store editors. In the foreground are large cards, each of which is dedicated to one application. It is clear that from the point of view of user convenience this is a dubious innovation.
On the other hand, if you want to quickly understand what the recommended apps are, then perhaps this interface can be called informative.
Stickers from apps in Messages
Another interesting and potentially useful, but far from as necessary as it seems, appearance in “Messages” easy access to stickers from third-party applications.
Now at the bottom of the Messages window there is a panel with icons of applications in which stickers are available. Moreover, you can either install some sets in the App Store, and they will become available here, or use the stickers that are in previously installed applications.
In particular, the screenshots show that Lara Croft 2, Solar Walk 2, and even the application for art lovers Artsy have stickers. This means that the range of stickers and their ease of use increases significantly. But... how often do we use “Messages”? In our case, communication usually takes place in Telegram, Viber, Whatsapp and even Facebook Messenger, not in Messages. We usually go there to write SMS, but in the case of SMS, stickers will not work.
New iPad interface
As we have already noted, the main changes affected the tablet interface. There is now a dock at the bottom of the screen, much like the one we're used to in macOS. Moreover, the most frequently launched applications automatically appear on the right side, and on the left you, as before, can add applications yourself.
The fundamental innovation is that the Dock can now be opened while inside any application. To do this, just perform a gesture of waving your finger from the bottom edge of the screen.
If we perform the same action while on the main screen and not in the application, we will see thumbnails open windows, like Mac's Spaces.
In addition, Apple is expanding multitasking capabilities in iOS 11 for iPad. In Split View mode, an additional application can be opened directly from the dock, and it will appear on the same screen along with the previously opened one.
Another interface innovation is the ability to switch between applications by pressing the oblong side button. Now the window thumbnails are arranged in a vertical row, and you can use both the screen and the wheel to navigate through them.
Other useful changes
In “Notes” there is now an option “Scanning documents”. In theory it looks really cool: you can take a photo of a document and the image will automatically be enhanced to look like it was a good scan. In practice it doesn't work very well yet.
Firstly, the option itself is hidden deeply. You need to create a new note, find the plus sign in the lower right corner, click on it and select “Scan documents.”
Secondly, the result is still not as good as is required for full use of the option. For example, the age-old problem of photography - light falling from above and creating unnecessary shadows - is only partially solved by this function. Below you can see that when photographing the document, although the picture was straightened and the shadow was partially removed, there were still dark spots that made serious work with this document impossible.
It would seem, why can’t the program understand that the spot below is clearly something extra? This cannot be on the documents! But - alas. However, this is definitely a move in the right direction, so let's hope things improve in iOS updates.
In addition to the above, it is worth describing the new capabilities of working with the Apple Pencil stylus (it is clear that this only applies to the iPad Pro).
Now you can draw in notes and letters, and the text will automatically “flow around” the drawing. You can also create a handwritten note directly on the lock screen (it will be saved in Notes). Plus, work with the stylus in PDF documents and screenshots has been improved - you can draw at any time, and the changes will be automatically saved.
conclusions
In this review, we haven't covered everything about iOS 11. The new version of the operating system has many small changes that may be interesting in themselves, but they are unlikely to be decisive. However, there are many major innovations described in the article.
Another thing is that we don’t have the feeling of any fundamentally new opportunities that have opened up after updating to iOS 11. Perhaps the notification feed on the lock screen and the ability to customize the Control Center are convenient. Otherwise, everything seems to be fine, but if you use iOS 11 and then return to iOS 10, there is no feeling of discomfort.
So, for example, expanding the capabilities of working with a stylus is absolutely the right direction, but how many users constantly carry the Apple Pencil with them? Yes, probably those who are really used to working with the Apple Pencil will like the new features, but they are in the minority.
The appearance of “Files” is completely doubtful in the form in which it is implemented now. It is not a full-fledged file manager. Strictly speaking, it is an aggregator of cloud services, nothing more. Previously, almost all the same things could be done simply using separate applications Dropbox, Google Drive, etc.
Another thing is that the direction of thought is absolutely correct. Yes, the work with files needs to be improved. Yes, the document scanning function can indeed be very useful if it is developed to the required level.
What is definitely convenient and good is the customized Control Center on the iPhone and the updated Dock on the iPad. However, you may have a different opinion and impression. Tell us in the comments which iOS 11 innovation you liked the most!
