Differences between Android devices and iPhones
Many of the most popular smartphones and tablets right now are based on "Android", but what is Android and how does it compare to iPhones and iPads?
Android is an operating system for smartphones and mobile devices like tablets. iPhones and iPads use an operating system called "iOS", differentiating them from Android devices which run the Android operating system.
So what are the main differences?
Multiple manufacturers vs. just one manufacturer
Android devices are sold and manufactured by lots of different companies, each releasing phones that look different and have different features to each other, yet all of them containing the Android operating system. In contrast to this, the iOS operating system behind iPhones and iPads is only available from a single manufacturer: Apple Inc.
The reason for this comes from the way the operating system is licensed: in simple terms, the creators of Android have allowed it to be used by any manufacturer who wishes to. Apple, on the other hand, do not allow any other manufacturers to use iOS on their devices.
The result is that you will see a huge range of different Android phones and tablets in competition with each other, with varying designs, sizes, and feature lists, in a range of different price ranges. The greater variety allows greater choice: you can buy a phone with or without a removable battery, with a high resolution or low resolution screen, with or without support for features like a MicroSD card reader or NFC - even phones that are (mostly) waterproof or support a pressure-sensitive stylus.
Apple, on the other hand, prefer to retain complete control over the manufacture and design of devices bearing their system, leading to a much narrower range of choices but therefore higher consistency between devices: they all look similar and have similar features.
Basically all smartphones and tablets support apps - small applications or games you can install on your device - and the primary way of finding and installing these apps is with an app store.
Android and iOS each have their own, separate app stores. Android devices usually (with few exceptions) access the Google Play store, whereas iOS devices always use the Apple iTunes app store.
Both stores contain millions of apps, including free apps and paid apps, games, utilities and productivity apps. Developers can create and offer their own app for sale or free download in either or both app stores. However, both of these app stores are separate; you can't install apps from the Apple iTunes app store on Android devices, and you can't install apps from the Google Play store or any other Android app store on iPhones or iPads. In practice most of the highly popular apps will be available in both stores, but not all apps are.
Alternative app stores or "sideloading"
While Apple only allow installation of apps onto iPhones or iPads from their own Apple iTunes app store, Android users may, if they wish, install alternative app stores or even install apps directly, without the need for an app store. While this practice may be somewhat rare, it is seen as an important indicator by some that Android gives users more freedom: the freedom to run apps without approval by Apple or Google.
Android devices sold by Amazon have access to an additional app store: the Amazon Appstore for Android. This is an alternative app store to the Google Play store available for Amazon-branded devices. There are other alternative app stores for Android that are available to anyone with an Android device. Some other alternative app stores may even be found in the Google Play store itself.
Installing an app without the aid of an app store is sometimes referred to as "sideloading". Sideloading is supported by Android devices (albeit only after enabling a special setting) whereas sideloading is not allowed at all on Apple devices.
Transferring files between the device and your computer
While both Android devices and iPhones/iPads let you store images, music, videos and more on your device, the method for transferring these files between the device and a computer is quite different.
An Android device can usually be plugged directly into any computer (whether Windows, Mac or Linux) and the files on the phone can be accessed as a drive - just as if you had plugged in an extra hard drive. You can copy files to and from your device just as you would with an external hard drive, putting your music, videos, and documents into folders of your choice on the device. You can also copy files back to your computer again.
By contrast, you can't access the files on your iOS device (iPhone or iPad) this way. Connecting an iPhone or iPad to your computer may let you, at most, access the photos you have taken with the device's camera. However, you cannot treat it like a portable hard drive, or copy files to or from the device, or access music or documents as if it's a connected drive. You may copy music or videos to your device, but in order to do so you must use the iTunes software. iTunes is available for both Windows and Mac.
Customisation of software
The Android operating system offers more ways of customising the design, behaviour and software features of the operating system when compared to iOS.
For example, Android allows users not only to add apps and widgets to the device's home screens, it also allows users to replace the home screen altogether with a separate home screen app. This is not currently possible with iOS. Similarly, Android allows replacement of most other built-in apps such as the on-screen keyboard app, the messaging and phone calls app, with third-party alternatives available from the Google Play store or other sources. This allows for the use of very different styles of home screens or on-screen keyboards should the user wish to try something different.
By contrast, iOS does not allow the replacement of the home screen or keyboard and offers relatively limited options for customising these either in appearance or behaviour.
It is this same ability to customise and replace the software experience on Android that also allows phone manufacturers themselves to customise the operating system, and as a result most Android devices sold by major manufacturers will use special custom home screen apps, keyboard apps and other apps provided by that manufacturer. As a result, there is no one single "Android look and feel" but a selection of different looking software interfaces from different manufacturers. While each will have the ability to install Android apps and basically work in the same way (having mostly the same functionality "under the hood"), the appearance of the default home screens and certain apps will vary between Android devices.
Most manufacturer-specific customisations can be overridden or overcome by users by replacing the relevant app: chiefly, the home screen app can be replaced with a third-party app should the user not like the home screen layout or appearance provided by the manufacturer.
By contrast, iOS devices always have the same, Apple-designed home screen and other apps, because they are only available from Apple.