What Is the iPhone OS (iOS)?

iOS is the name of the operating system for the iPhone, iPad, and more

iOS 11 press image featuring an iPad and an iPhone
Apple iPhone & iPad (iOS 11). © Apple Inc.

iOS is Apple's mobile operating system used to run the popular iPhone, iPad, and iPod Touch devices. Formerly known as the iPhone OS, the name was changed with the introduction of the iPad.

iOS utilizes a multi-touch interface where simple gestures are used to operate the device, like swiping your finger across the screen to move to the next page or pinching your fingers to zoom out. There are over one million iOS applications available for download in the Apple app store, the most popular app store of any mobile device.

Much has changed since the first release of iOS with the iPhone in 2007. See our iOS Version History for all the new features and fixes since that initial release.

What is an operating system?

In the most simple terms, an operating system is what lies between you and the physical device. It interprets the commands of software applications ("apps"), and it gives those apps access to features of the device, such as the multi-touch screen or the storage.

Mobile operating systems like iOS differ from most other operating systems because they put each app in its own protective shell, which keeps other apps from tampering with them. This makes it impossible for a virus to infect apps on a mobile operating system, although other forms of malware can and do exist. The protective shell around apps also poses limitations because it keeps apps from directly communicating with each other. iOS gets around this by using extensibility, a feature that essentially lets an app have the approval to communicate with another app.

See our What is an Operating System? for more on OSs and how they work.

Can you multitask in iOS?

Yes, you can multitask in iOS. Apple added a special form of 'limited' multitasking soon after the release of the iPad. This multitasking allowed processes such as those playing music to run in the background.

It also provided fast app switching by keeping portions of the app in memory even when they weren't in the foreground.

Apple later added features which allow some iPad Models to utilize Slide-Over and Split-View multitasking. Split-View multitasking splits the screen in two, allowing you to run an individual app on each side of the screen.

See How to Multitask on an iPad for help doing this.

How much does iOS cost? How often is it updated?

Apple does not charge for updates to the operating system. In fact, Apple also gives away two suites of software products with the purchase of iOS devices: The iWork suite of office apps, which includes a word processor, spreadsheet and presentation software, and the iLife suite, which includes video editing software, music editing and creation software, and photo editing software. This is in addition to apps like Safari, Mail, and Notes that come preinstalled with the operating system. See our list of Apple's iPad apps for a description of all of the software you get with an iPad or iPhone.

Apple releases a major update to iOS once a year, with an announcement at Apple's developer conference in early summer followed by a release in early fall timed to coincide with the announcement of the most recent iPhone and iPad models.

These free releases add major features to the operating system, such as the virtual touchpad added in the iOS 9 release. Apple also does bug fix releases and security patches throughout the year.

Should I update my device with each minor release or only worry about the big iOS releases?

It is very important to always update your iPad or iPhone even when the release seems minor. While it may sound like the plot of a bad Hollywood movie, there really is an ongoing war - or, at least, an ongoing tugging match - between software developers and hackers. The small patches throughout the year are often aimed at patching holes in the security layer that hackers have found.

Apple has made it easier to update devices by allowing us to schedule an update at night.

How do I update my device to the newest version of iOS?

The easiest way to update your iPad, iPhone or iPod Touch is to use the scheduling feature. When a new update is released, the device will ask if you want to update it at night. Simply tap "Install Later" on the dialog box and remember to plug your device in before you go to bed. This feature was introduced with iOS 9, so you will need to at least be on that version for this to work.

You can also install the update manually by going into the iPad's settings, selecting General from the left-side menu and then selecting Software Update. This will take you to a screen where you can download the update and install it on the device. The only requirement is that your device must have enough storage space to complete the process.

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