Android (operating system) facts for kids
Wordmark and logo used since 2023
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| Company / developer | Various (mostly Google) |
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| Programmed in | Java, Kotlin (UI), C (core), C++, Rust and others |
| OS family | Unix-like (modified Linux kernel) |
| Working state | Current |
| Source model | Open source, freeware (most devices include proprietary components, such as Google Play Services or One UI) |
| Initial release | September 23, 2008 |
| Latest stable release | Android 14 / October 4, 2023 |
| Latest unstable release | Android 15: Developer Preview 2 / March 21, 2024 |
| Marketing target | Smartphones, tablet computers, smart TVs (Android TV), Android Auto and smartwatches (Wear OS) |
| Package manager | APK-based |
| Supported platforms | ARM64 (previous versions were also compatible with ARMv7, x86, x86-64, MIPS and RISC-V; these architectures are still unofficially supported via third-party solutions) |
| Kernel type | Monolithic (Linux kernel) |
| Userland | Bionic libc, mksh shell, Toybox as core utilities |
| Default user interface | Graphical (multi-touch) |
| License |
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Android is a popular mobile operating system. It's like the main program that runs on your smartphone or tablet. Android is based on a special version of the Linux kernel and other open-source programs. This means its basic code is available for anyone to see and use.
Google mostly develops the Android version that most people use. The first Android device, the HTC Dream, came out in September 2008. Android is now the most used operating system in the world for smartphones and tablets. It has billions of users!
The main part of the operating system is called the Android Open Source Project (AOSP). It's free to use. However, most Android devices also come with extra programs from Google, like Google Play (where you get apps) and Google Chrome (for browsing the internet). These extra programs are not open-source.
Many phone companies, like Samsung, make their own changes to Android. They add their own look and features. Some companies, like Amazon, even make their own versions of Android, like Fire OS.
Android is used on many devices, not just phones and tablets. You can find it on smart TVs (called Android TV) and smartwatches (called Wear OS). Apps for Android usually come in a file format called APK. You can download them from app stores like Google Play Store or Amazon Appstore.
Contents
How Android Started
Android Inc. was started in 2003 by Andy Rubin and his friends. At first, they wanted to make an operating system for digital cameras. But they soon realized that making an OS for phones would be a much bigger idea.
It was hard for them to find people to invest money at first. But then, a friend of Andy Rubin, Steve Perlman, helped them out with some cash.
In 2005, Google bought Android Inc. for about $50 million. This was a great deal for Google! The Android team, including Andy Rubin, joined Google. They worked on making a mobile platform using the Linux kernel. Google wanted to offer phone makers a flexible system that could be updated easily.
When the Apple iPhone came out in 2007, it changed everything. The early Android prototypes looked like BlackBerry phones with physical keyboards. But after the iPhone, Android quickly switched its focus to touchscreens. The very first Android smartphone, the HTC Dream (also known as T-Mobile G1), was released in September 2008.
In November 2007, a group of tech companies, including Google, HTC, and Samsung, formed the Open Handset Alliance. Their goal was to create a truly open platform for mobile devices.
Since 2008, Android has had many updates. Each major update used to be named after a dessert or sweet treat, like "Cupcake" or "Donut". But in 2019, Google stopped this tradition. Now, new versions are just called by their number, like Android 10 or Android 14.
Google used to make its own phones called the Nexus series. These phones were known for getting new Android updates very quickly. Later, Google launched the Pixel phones, which are also made by Google and get the latest Android features first.
What Android Can Do
Android's design is based on touching the screen. You use your fingers to swipe, tap, and pinch. It also has a virtual keyboard for typing. You can connect Game controllers and keyboards using Bluetooth or USB.
Android devices use sensors like accelerometers and gyroscopes. These help apps respond to how you move your device. For example, a racing game might let you steer by tilting your phone.
How You Use the Interface
When you turn on an Android device, you see the home screen. This is like your computer's desktop. It has app icons and widgets. Icons open apps, while widgets show live info like the weather or your emails. You can have several home screen pages and swipe between them.
At the top of the screen is the status bar. It shows things like battery life and Wi-Fi signal. You can pull it down to see notifications and quick settings. This is where you can turn on Wi-Fi or adjust screen brightness.
Notifications are short messages from your apps. They tell you important things, like a new message or an update. You can tap on them to go right to the app.
There's also an "All Apps" screen that lists every app you have. You can drag apps from this list to your home screen. A "Recents" screen lets you switch between apps you've used lately.
Older Android phones had physical buttons for "Home," "Menu," and "Back." Newer phones often use on-screen buttons or gestures.
Android also has a split-screen view. This lets you use two apps at the same time, side-by-side. Samsung phones had this feature early on, and it became a standard part of Android later.
When your device is off and charging, you can usually see a battery icon. This shows you how much charge it has without turning it on.
All About Apps
Most Android devices come with Google apps already installed. These include Gmail, Google Maps, and YouTube.
Developers create Android apps using special tools called the Android software development kit (SDK). They mostly use the Kotlin or Java programming languages.
The SDK has tools like a debugger (to find problems in code) and an emulator (to test apps on a virtual phone). Google's main tool for making apps is Android Studio.
There are millions of apps available for Android. The Google Play Store is the main place to get them. You can browse, download, and update apps there. Other app stores exist too, like the Amazon Appstore. Some, like F-Droid, only offer free and open source apps.
In 2021, Microsoft added a way to run Android apps on Windows 11 computers. This was called the Windows Subsystem for Android (WSA), but it has since been removed.
How Android Stores Information
Android devices can use SD cards to add more storage. You can use an SD card as "portable" storage, like a USB drive. Or, you can make it "adoptable" storage. This makes the SD card act like it's part of the phone's internal memory. But if you do this, you can't easily use the SD card with other devices.
Android also has rules about how apps can access your files. This is called "scoped storage." Apps can only access certain folders (like pictures or music) automatically. For other files, they need to ask your permission.
Managing Memory
Android is designed to save battery power. When you're not using an app, Android pauses it. This means the app isn't using power or your phone's processor. If your phone is low on memory, Android will automatically close apps that haven't been used in a while.
Developer Settings
Android has a hidden "Developer options" menu. This is for people who develop apps or advanced users. It has settings for things like debugging apps or changing animation speeds. You can unlock it by tapping the "Build number" in your phone's settings seven times.
How Android Hardware Works
Android runs on different types of computer chips. Most Android phones use ARM chips. But it also supports x86 chips, which are found in many computers.
Android devices can have many different parts, like cameras, GPS, and various sensors. These sensors help your phone know how it's being held or where it is. Not all parts are required. For example, older Android phones needed a microphone, but now that Android is used on TVs, a microphone isn't always needed.
Android can even run on regular computers with a keyboard and mouse. Some companies are making Android-based operating systems for PCs to compete with Windows.
How Android is Developed
Google develops Android behind the scenes. When a new version is ready, Google releases its source code to the Android Open Source Project (AOSP). This project is led by Google, and the code is available for everyone to use and change.
Most phone makers take this AOSP code and change it to work with their specific phones. They also add their own features and designs.
The AOSP code doesn't include all the parts needed for a phone to work. For example, it doesn't have the special programs (drivers) for certain hardware. It also doesn't include Google Play Services, which many apps need. So, most Android devices use a mix of open-source and private software.
Updates for Android
Google releases new versions of Android every year. These updates add new features and fix problems. However, getting these updates to your phone can take time.
This is because there are so many different Android devices. Each update has to be specially changed for each phone model. Phone makers often update their newest phones first, leaving older ones behind. Wireless carriers (like your phone company) can also cause delays because they test updates on their networks.
To help with this, Google started separating some parts of Android. Now, some parts can be updated through the Google Play store, just like apps. This means Google can add new features and fix bugs without needing a full operating system update.
In 2017, Google launched Project Treble. This project makes it easier for phone makers to update their devices to newer Android versions. It separates the main Android system from the parts that are specific to each device's hardware. This way, phone makers don't have to do as much work for each update.
In 2019, Google introduced Project Mainline. This allows core parts of Android to be updated through the Google Play Store. This means important security and performance updates can be delivered faster, just like app updates.
The Linux Kernel
Android uses a special version of the Linux kernel. The kernel is the core part of an operating system that manages the hardware. Android's kernel is based on the long-term support (LTS) versions of the Linux kernel.
Even though Android uses the Linux kernel, it's different from the Linux you might find on a desktop computer. Android doesn't use all the same parts.
Rooting Your Device
Android devices have different storage areas. One is for the operating system, and another is for your apps and data. Normally, you don't have full control over the operating system part.
"Rooting" an Android device means getting full control over it. This lets you change things that you normally can't. People in the open-source community often root their devices to add new features or customize them. However, rooting can also make your device less secure.
How Android Software Works
Android apps run in a "sandbox." This is like an isolated area that keeps the app from accessing other parts of your phone without permission.
Android uses something called Android Runtime (ART) to run apps. When you install an app, ART translates its code into a language your phone understands. This makes apps run faster.
Security and Privacy
Google has a security team for Android. They work to make Android safer.
Common Security Issues
One common problem is "premium service abuse." This is when bad apps send text messages from your phone to expensive numbers without you knowing. Other bad apps might show you unwanted ads or send your personal information to others.
Google says that serious malware on Android is actually rare. They believe that security companies sometimes make the threat seem bigger to sell their antivirus software. Most Android malware doesn't come from the Google Play Store.
In 2021, a type of spyware called Pegasus was found. This software could infect both Android and iPhone devices without you even knowing. It could steal your data, track your location, and even turn on your camera and microphone.
How Public Institutions Use Data
In 2013, it was revealed that some government agencies could access user data from Android phones. They could read texts, see your location, and look at emails. This raised concerns about privacy.
Security Updates
Google started sending out monthly security updates for its Nexus phones in 2015. But for other Android phones, updates can be slow. This is because phone makers and carriers have to customize and test each update.
Google is working to make updates faster. They've introduced things like Project Treble and Project Mainline to help. They also encourage phone makers to provide updates more quickly.
Location Tracking
Android phones can report the location of Wi-Fi hotspots you pass by. This helps create maps that can locate smartphones. This information is used by apps like Google Maps and for location-based ads.
Other Security Concerns
In 2018, a security flaw was found that could let bad apps steal your login info or track your location. This flaw affected all versions of Android. It allowed a bad app to show fake login screens over real apps.
In 2020, a report said that many older Android devices (from 2012 or earlier) were at risk of being hacked. This was because they no longer received security updates.
Technical Security Features
Android apps run in a "sandbox." This means each app is kept separate from others. This helps prevent a bad app from messing with other apps or your system. However, some pre-installed apps might have more access.
Google has a system called "Google Bouncer" that scans apps in the Google Play Store for malware. There's also a "Verify Apps" feature that scans all apps on your device for bad behavior.
When you install an app, the Google Play Store shows you what permissions the app needs (like access to your camera or contacts). You can choose to accept or deny these. Since Android 6.0 "Marshmallow," you can also grant or deny individual permissions when an app needs them for the first time.
Android also has a "Find My Device" service. This lets you track, locate, or erase your Android device remotely if it gets lost or stolen.
Android uses a "verified boot" system. This checks that the software running on your phone is official and hasn't been tampered with. This helps protect against malicious software.
Licensing and Control
The basic source code for Android is open-source. Google releases most of it under the Apache License. This license allows people to change and share the code. However, the "Android" name and logo are trademarks of Google. Phone makers need a special license from Google to use them.
Only the core Android system is open-source. Most Android devices also come with Google's own private software, like Google Play Store and Google Play Services. Phone makers have to license these from Google.
Some people, like Richard Stallman from the Free Software Foundation, are critical of Android. They say that because many important parts are not open-source, it can lead to privacy and security risks.
Google's Influence on Manufacturers
Google has rules for phone makers who want to use Google Mobile Services (like the Play Store) and the Android brand. Devices must meet Google's compatibility standards.
This means that if a company makes big changes to Android, they can't include Google's private apps. For example, Amazon's Fire OS is a version of Android that focuses on Amazon's services instead of Google's.
Google also requires phones that use its services to show a "Powered by Android" logo when they start up. Google also encourages phone makers to put Google apps front and center on their devices.
Some parts of the original open-source Android code, like the old Search or Music apps, have been replaced by Google's own private versions. This makes it harder for other companies to create their own versions of Android without using Google's services.
Other Ways Android is Used
Google has made special versions of Android for different devices:
- Wear OS for smartwatches.
- Android TV for televisions.
- Android Automotive for cars.
Because Android is open and flexible, device makers use it in many other electronics. You can find Android in:
- Laptops and desktop computers
- Cameras
- Headphones
- Home automation systems
- Game consoles like the Ouya and Nvidia's Shield Portable
- Media players
- Printers
- Payment terminals
- Even coffee machines and refrigerators!
In 2011, Google showed "Android@Home," a system to control home devices like lights and power outlets using Android.
Car companies are also using Android. The Open Automotive Alliance is a group that includes car makers like Audi and Honda, working to put Android-based entertainment systems in cars.
Android can even be installed on regular personal computers. It has features for keyboards and mice, like using "Alt-Tab" to switch between apps.
Google also explored virtual reality with Google Daydream. This platform used a smartphone and a special headset to provide VR experiences, but it was later stopped.
Android's Mascot
The mascot for Android is a green robot. The Android team at Google calls it "Bugdroid." In 2024, Google officially named it "The Bot."
A graphic designer named Irina Blok created the robot in 2007. She made it open source, so anyone could use it. The robot quickly became popular with the Android developers, and Google eventually made it the official mascot.
See also
In Spanish: Android para niños
- Comparison of mobile operating systems
- Index of Android OS articles
- List of Android smartphones
- Custom Firmware § Android
