Angela Yu

iOS is Apple’s mobile operating system for its range of mobile devices. That is, it’s the underlying system software running on iPhones, iPads, and iPod Touches. If you own one of these devices, then you can be sure that it’s using iOS.

In this article, we’ll cover the history of Apple’s mobile operating system and how beginners can get started in app development. First, let’s understand the foundation of it all, with a deep dive into software operating systems.

iOS & Swift – The Complete iOS App Development Bootcamp

Last Updated November 2023

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From Beginner to iOS App Developer with Just One Course! Fully Updated with a Comprehensive Module Dedicated to SwiftUI! | By Dr. Angela Yu, Developer and Lead Instructor

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What is an operating system?

An operating system (OS) is the system software that manages a device’s hardware, provides services to other installed software, and offers the user an interface with which to interact. For example, Windows is the Microsoft operating system that’s popular for home and professional use and runs on a range of desktops and laptops. A mobile operating system is simply an OS for mobile devices like tablets and smartphones. 

iOS is Mac’s mobile operating system and was originally based on the Mac computer OS, a UNIX variant. The other well-known mobile operating system (OS) is Android, although there are other lesser-known mobile OSs, such as Amazon Fire OS (based on Android), and Chrome OS.

iOS is well regarded in terms of security thanks to its strict APIs and governance of apps that can be used on the platform. Users and developers can expect regular small updates to tweak and improve the experience as well as patch security vulnerabilities. Major releases (like the move from iOS 12 upgrade to iOS 13) happen once a year and carry significant feature updates. 

Apple’s iOS comes preloaded with a range of default Apple apps, which is software produced by Apple, such as the Safari web browser and Apple Music for audio streaming.

The operating system for Mac desktops and laptops is named MacOS. Unlike Windows operating systems, it only runs natively on Apple-branded devices. For Apple TVs, it’s tvOS, and for Apple Watches, watchOS.

What is iOS? Facts and figures

Original release date: June 29, 2007 (as iPhone OS 1)

Current version: iOS 13.3.1 (as of January 28, 2020)

Software Development Kit: XCode 11.4 Beta (as of February 5, 2020)

iOS 13 devices supported: iPhone 11, iPhone 11 Pro, iPhone 11 Pro Max, iPhone XS, iPhone XS Max, iPhone XR, iPhone X, iPhone 8, iPhone 8 Plus, iPhone 7, iPhone 7 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPod touch (7th generation)

Current number of iOS apps in the App Store: Just over 2.5 million as of Q4 2019, according to Statistica

Where does the ‘i’ in iOS come from?

The ‘i’ prefix seen in Apple products, such as the iPhone, iPad, iCloud, and iTunes, has been a staple throughout Apple’s marketing messaging since 1998.

The iMac, Apple’s first i-associated product, was unveiled in a legendary Steve Jobs keynote speech when Apple announced the original iMac with the tagline “The excitement of the internet. The simplicity of Macintosh.” Speaking about the iMac shortly after at the Apple Worldwide Developers Conference, Jobs spoke with candor on how competitors don’t know how to market a product. He believed the world wanted fashionable products. His reference to the average consumer once only owning one watch, but now owning seven because of fashion choices, is amusing now that smartphones have nearly superseded the need for watches altogether.

Following the iMac came the iBook notebook computer, iPods, and the rest of the i- family. It’s only natural that Apple operating systems would also adopt this naming strategy.

iOS wasn’t always called iOS 

When the iPhone was first released in 2007, the original OS was dubbed iPhone OS; it was also the operating system for the iPod Touch. Rebranding to iOS came in 2010 and required licensing the name from Cisco, who owned the rights to the name IOS, which was used for its network operating system. 

This licensing stir with Apple releases also mirrored the iPhone release. Cisco had already trademarked the iPhone name in 2000, with the Linksys iPhone released mere weeks before Apple’s iPhone announcement.

Developing apps for iOS: iOS developer options

Browser-based apps and progressive web apps

When the iPhone was first released, Steve Jobs wanted the App Store to only offer Apple-created apps. Third-party developers could simply develop their own apps to run on the browser. Thankfully, this idea was soon scrapped and led to the rise of mobile apps. 

Perhaps prophetically, many developers now choose to develop web apps for the mobile browser. Progressive web apps (PWAs) offer more hardware support, but don’t require going through a stringent process to get accepted on the App Store.

Web apps for mobile

Web apps for mobile don’t require any iOS-specific development skills. You can develop using regular web app technology while keeping in mind iPhone screen size, load times, etc. If you’re building a mobile web app, you can have it work the same on Android too, just remember to test on a range of browsers: Safari, Chrome, Firefox, etc.A generalized web developer course, such as The Complete Web Developer Course 2.0, can give you a start in web development overall, including HTML-based mobile apps for the browser (which will also work on Android devices, too).

Progressive web apps

Progressive web apps (PWAs) are considered a step up from web apps. They receive more support from the operating system in order to behave like regular mobile apps. This includes features like running in the background, showing via the app switcher, dark mode support, and other features that aren’t available in the browser. These are accessible via the Apple API. 

PWAs aren’t as useful on Apple devices as they are on Android devices, where developers can add things like push notifications. The advantage of PWAs is when programming for both mobile operating systems, code development becomes less redundant. While some elements must be programmed separately for each specific OS, there is far more overlap than developing natively. Check out Progressive Web Apps (PWA) – The Complete Guide for a comprehensive programming course.

Native iOS development for the App Store

iOS development refers to the development of an app for release on the App Store. This is known as native development and offers developers access to far more features than web or progressive web app development. Programmers should stay up to date with programming techniques for the latest major release, currently iOS 13, and minor releases as applicable to their apps for software updates.

To do native iOS development, you will need to use XCode (Apple’s iOS development system) and program with Swift, the user- and beginner-friendly coding language for Apple systems that makes app development very straightforward. Try out iOS 13 – How to Make Amazing iPhone Apps: Xcode 11 & Swift 5 for an introduction to native development.

There are a number of rules you’ll need to follow to get an app accepted to the App Store and the review process may take some time and edits before your app goes live.

Native iOS development for internal apps 

Plenty of organizations have no desire to publish their apps on the public App Store — these are apps developed for internal use only. Think business applications for use on company iPads or iPhones, or for use with a Bring Your Own Device policy.

The Apple Developer Enterprise Program is the way to build these types of apps. There are various rules which must be adhered to, such as enterprise security and sign-on systems, but it bypasses the App Store used for public apps.

For enterprise apps, Apple’s new Single Sign-On service, introduced with iOS 13, offers greater organizational security. Udemy instructor, Nick Walter, elaborates on the advantages of Single Sign-On in The Best New iOS 13 Features to Enhance Your Apps:

“Arguably the most significant change in iOS 13 for developers is the introduction of Apple’s own Single Sign-On (SSO) solution for logging into apps. SSOs offer a convenient way to let your app’s users sign in without having to create a new account and password.

A helpful aspect of Sign in with Apple is the use of FaceID, TouchID, and on-phone gyroscope to confidently indicate whether a real human user (an employee, contractor, or client) or a bot is signing into an app.”User Enrollment for Mobile Device Management combined with Single Sign-On makes for a far more secure and cohesive operating environment for companies. You can learn more about extensible enterprise Single Sign-On in this video from Apple.


Was the Apple iPhone the first smartphone?

No, early smartphones included the Blackberry series and T-Mobile Sidekick and were usually targeted at business users rather than consumers. The first ‘Apple mobile’ was not even a smartphone, but the Motorola ROKR E1 which came loaded with iTunes.

What’s the iOS market share for mobile OSs?

According to StatCounter, in Q4 2019, iOS accounted for 24.76% of the world’s mobile OS market space, vs Android’s 74.3%. In the US, however, it accounted for 57.42%, vs 42.35% for Android. iOS has an increased market share in many developed countries.

Is each iOS update automatic?

You can choose whether an iOS device updates its operating system automatically over Wi-Fi when available or requires a prompt to update. While Control Center houses plenty of handy shortcuts, to find the iOS version you will need to visit Settings — General — About and then scroll to find the Software Version. If you’re running iOS 13, it will display 13.X.X. To enable automatic iOS updates, visit Settings — General — Software Updates and toggle on Automatic Updates.

What is iPadOS?

iPadOS is a new addition to the suite of Apple operating systems. It’s designed specifically for iPads and offers more targeted functionality, with split views and more multi-touch features. If you are designing an app specifically for iPads, developing for iPadOS may offer better feature support.

Can iPad and iPad Pro apps be ported to Mac computers?Apps for iPad and iPad Pro can now be ported to Mac computers with Project Catalyst. As Walter explains, “With just the tick of a single checkbox in Xcode, developers can add MacOS functionality to the iPad or iPhone apps they’ve developed with Swift code. However, don’t just blindly repackage an iPad app as a desktop app. Take the time to consider a desktop user’s different needs and use cases.”

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