Android (operating system)

Android is an operating system owned by Google, based on a modified version of the Linux kernel and other free and open-source software. It was designed mainly for touchscreen-based mobile devices like smartphones and tablet computers. First released in 2008, Android has become the world's most widely used operating system, especially for smartphones.

The core of Android is called the Android Open Source Project (AOSP), which is free and open-source software licensed under the Apache License. However, most devices use a version developed by Google, which includes extra tools like Google Mobile Services. These tools have important apps such as Google Chrome and the Google Play store where people can download more programs.

Android can be found on many types of devices beyond just phones and tablets. There are versions for televisions called Android TV, for wearable devices known as Wear OS, and even for car systems named Android Automotive. Because Android is open-source, many companies have made their own versions, such as Amazon Fire OS and community-developed LineageOS.

Software for Android comes in a special format called APK and is usually downloaded from app stores. While Google's Google Play is the most common, there are other stores like Amazon Appstore, Samsung Galaxy Store, and Huawei AppGallery. Since 2011, Android has had the most users of any operating system in the world, with over three billion people using it each month.

History

See also: Android version history

2000s

Android Inc. started in Palo Alto, California in October 2003 by Andy Rubin and Chris White, with Rich Miner and Nick Sears joining later. Rubin had previously worked on the T-Mobile Sidekick with his company Danger, Inc.. They began by trying to build an operating system for digital cameras, but later switched to focus on phones.

In 2005, Google bought Android Inc. for at least $50 million. The team continued to develop a mobile platform using the Linux kernel. Google shared this platform with phone makers and carriers, promising a flexible and upgradeable system.

In November 2007, the Open Handset Alliance, a group of technology companies including Google, device makers like HTC, Motorola and Samsung, and wireless carriers like Sprint and T-Mobile, was formed to create an open platform for mobile devices.

The first Android phone, the HTC Dream (also called T-Mobile G1), was announced on September 23, 2008.

Since 2008, Android has been updated regularly with new features and fixes.

2010s

In 2010, Google started the Nexus series, working with device makers to create phones that introduced new Android versions with clean software and quick updates.

In 2014, Google began the Android One program to make it easier for device makers to create affordable phones, especially for users in developing countries.

In October 2016, Google introduced the Pixel and Pixel XL smartphones, the first phones made by Google, featuring exclusive software like the Google Assistant.

In May 2019, Android's development was affected by trade issues between China and the United States, impacting companies like Huawei.

On August 22, 2019, Google announced that Android would no longer use dessert names for its versions. Android 10 was released on September 3, 2019, for Google Pixel phones first.

2020s

In late 2021, some users had trouble calling for emergency help because of bugs in Android and the Microsoft Teams app. Both companies fixed the problem with updates.

On December 12, 2024, Google announced Android XR, a new operating system for virtual reality and augmented reality devices, developed with Samsung and Qualcomm.

In March 2025, Google planned to focus Android development internally, though the Android source code will still be shared publicly.

Features

Main article: List of features in Android

Android's main way of working is through touching the screen. Users can swipe, tap, and pinch to do things like open apps and play games. The phone also works with game controllers and physical keyboards using Bluetooth or USB.

When you turn on an Android phone, you see the home screen. This is like a desktop on a computer, with app icons and widgets. Widgets show live information like the weather or news. You can swipe through many home screen pages. Some phone makers change how the home screen looks to make their phones special.

At the top of the screen is a status bar. Pulling this down shows important updates and lets you control things like brightness, WiFi, and Bluetooth.

Android phones come with Google apps like Gmail, Maps, Chrome, and YouTube. Users can also get new apps from places like the Google Play Store. These apps make the phone do more things, like taking pictures or playing games.

Android phones can also have more storage using SD cards. The phone manages its memory to save battery, closing apps that aren’t being used when memory gets low. There are special settings for developers, but these are usually hidden unless you know how to find them.

Hardware

See also: Android hardware requirements

Android mainly works on 64-bit ARM and 32-bit ARMv7-A computers, but it can also run on x86-64 and 32-bit x86 computers. The Android-x86 project helped make this possible before it was official. Since 2012, phones and tablets with Intel processors have been available. Android later added support for 64-bit ARM64 computers, and there was an unofficial version for 64-bit RISC-V computers in 2021. Support for 32- and 64-bit MIPS computers was available at one time.

Smartphones running Android 15 need at least 2 GB of memory if they use the Android Go Edition, or 4 GB for the full version. Android works with many types of graphics systems, including all versions of OpenGL ES and Vulkan.

Android devices can include many extra parts, like cameras, GPS, sensors to know direction, game controls, and touchscreens. Some of these parts are not required for all devices. For example, early Android devices needed microphones for phone calls, but later versions do not require this if the device does not make calls. Android can also run on regular computer hardware with a keyboard and mouse, thanks to projects like Android-x86 and emulators. Some companies in China are making their own versions of Android for computers to work like Microsoft Windows and Android.

Devices

Android can be found on many types of devices, like smartphones, tablets, cars, computers, smart watches, and smart TVs. But most Android devices are smartphones. Unlike some other operating systems, Android phones are made by lots of different companies. These companies include Samsung, Xiaomi, Vivo, Oppo, iQOO, OnePlus, Honor, Google, Sony, Lenovo, Sharp, Realme, Nothing, and Tecno.

Development

Android is developed by Google. When updates are ready, the source code is shared with the Android Open Source Project (AOSP), an open source group led by Google. The first source code release happened in 2007. All releases are under the Apache License.

The AOSP code can be found on some devices, like older Nexus and current Android One phones. But many device makers change the code to fit their hardware.

Android’s source code does not include certain parts needed for some hardware or for Google services. So, most Android phones use a mix of free and open-source software and proprietary software. Some projects try to build full operating systems using only free software based on AOSP, starting with CyanogenMod.

Update schedule

Google releases Android updates yearly for new devices and for updates to existing devices. The latest major version is Android 16.

Because Android devices have many types of hardware, updating software can take time. Each update must be tailored for different devices, which can cause delays. Updates often come months after the official release, or sometimes not at all, especially for older devices. Manufacturers focus on newer models, and wireless carriers also test updates before releasing them. Sometimes, updates can’t happen because device makers don’t update important parts of the system.

This lack of support has been criticized. In 2011, Google started the Android Update Alliance to promise timely updates for 18 months after a device’s release, but there hasn’t been much news since. In 2012, Google began updating some parts of Android through the Google Play store, separate from the main operating system updates. This helps add new features and fix issues without needing a full system update.

In 2017, Google introduced Project Treble to make updating Android easier and faster for device makers. This separates parts of the system so updates can happen more smoothly. In 2019, Project Mainline was introduced to allow important security and performance updates to be delivered through the Google Play Store, like app updates.

Google made changes in Android 12 to make it easier to use app stores other than Google Play, addressing concerns from businesses affected by COVID-19.

Linux kernel

Android uses a version of the Linux kernel. As of 2024, Android uses versions 6.1 or 5.15 of the kernel. Android’s version of the Linux kernel has special changes made by Google, such as support for device trees and different ways to manage memory. Some features Google added to the Linux kernel were not accepted by the main Linux developers at first, but later versions of the kernel included some of these features.

Rooting

Some people try to get full control, or “root access,” of their Android devices. This can be done by finding security problems in Android or by unlocking parts of the device that are normally locked. Getting root access lets people change the device more freely, but it can also let harmful software take control. Some phone makers allow users to unlock these parts, but doing so usually erases all data on the phone. Some protection systems, like Samsung Knox, try to stop people from getting root access.

Software stack

Android runs on top of the Linux kernel, with extra parts called middleware and libraries, and apps that use a framework including Java-like tools. Android uses a special runtime called Android Runtime (ART), which compiles apps ahead of time for better performance. Older versions used Dalvik, which used a different way to run apps.

Android uses a special C library called Bionic, made by Google, which is smaller and designed for mobile devices. Android also includes a separate small operating system called Trusty OS for secure tasks like handling payments or protecting personal data.

Open-source community

Because Android’s source code is open, many people and groups have created their own versions of Android. These versions can bring updates to older devices, add new features, or let Android run on devices that originally used other operating systems. These community versions often include changes not provided by the original maker, like letting people change how the device works or improving security.

CyanogenMod was a popular community version, but it stopped in 2016. A new version called LineageOS continued its work. Some device makers and carriers used to oppose these changes, but many now support or encourage this work. Some phones now come with ways to unlock parts of the system, making it easier to use community versions.

Device codenames

Android gives each device a special internal name, called a device codename. This name is not usually shown to users but helps developers know what hardware a device has. For example, the Pixel smartphone’s codename is “sailfish.” This name helps when talking about different versions of the same device.

Security and privacy

See also: Mobile security and Comparison of open-source mobile phones

In 2020, Google started the Android Partner Vulnerability Initiative to help keep Android safer. They also created a special team just for Android security.

Common security threats

Researchers from a security company found that one common problem with Android phones is when people get messages asking them to pay for services they didn’t ask for. Other problems include unwanted ads or private information being sent to places users don’t know about. Google says these bad things happen less often than some people think, and that very few dangerous problems come from the Google Play store.

In 2021, some people found software that could secretly watch or listen to what someone was doing on their phone. Phones sometimes share more information than needed, and users can’t always stop this.

Security patches

In 2015, Google said that some phones would get monthly updates to fix problems. But not all phones get these updates quickly, especially older or cheaper ones. Google tries to make updating easier, but it still takes time for all phones to get the latest fixes.

Location-tracking

Android phones can tell where Wi‑Fi spots are, which helps apps know where a person is. Some software can see when private information is being sent out from the phone.

Technical security features

Android apps usually run in their own space, so they can’t access other parts of the phone unless the user says it’s okay. Google watches the apps in its store to make sure they’re safe. Users can choose what information each app can see when they first start using it.

Android also has ways to check that the phone’s software hasn’t been changed by someone who wants to cause trouble. Google offers ways to find a lost phone or see where a friend is during emergencies.

Criticism and controversy

Privacy and GDPR compliance

In 2019, Google was fined a large amount of money by French officials for not giving enough information about how they use user data.

Later, in 2021, a researcher showed that even when an Android phone was not in use and had no Google account, it still sent some data to Google. In 2022, it was found that Android phones sent details about calls and messages to Google, even when certain settings were turned off.

In 2022, Google was also penalized in Australia for misleading people about how they collect location data from Android phones. This affected around 1.3 million users in Australia.

Short software support lifespans

Android devices, especially cheaper ones, have often stopped getting updates after just one or two years. This happens because companies sometimes don’t want to spend money on updating older devices.

To help fix this, Google created a new system to make updates easier. Some companies like Samsung have started offering longer support for their phones, but many cheaper phones still don’t get updates for very long.

Google's developer verification program

In 2025, Google announced that developers would need to register with Google to share apps on Android phones, whether through the Play Store or other ways. This rule will start in September 2026. Some people are concerned this will give Google too much control over which apps can be used.

Licensing

The source code for Android is open-source. Google develops it privately and releases the code publicly when a new version comes out. Most of the code is shared under the Apache License version 2.0, which allows changes and sharing. However, the "Android" trademark must be licensed from Google by device makers.

Only the basic Android system is open-source. Most devices also include special software from Google, like the Google Play Store and Google Search, which device makers must license separately. These additions help the devices work with Google's services. Some companies create their own versions of Android with extra features or different apps.

Some people feel that because device makers must pay for Google's branding and services, Android is not completely free. Google also sets rules for how Android can be used, which means some changes to Android cannot include Google's special software. This can limit what device makers can do with the system.

Reception

Android was first shown in 2007 and people were not sure how it would do. Some experts liked the big companies that joined with Google to help make it, but others were worried. They thought Android might not be strong enough to compete with big names like Nokia and Microsoft.

Since then, Android has become the most used phone system in the world. People like that it is open for anyone to use and change. This has let many different companies make their own versions of Android for their devices. It also lets phone owners change how their phones look and work, and people can find apps from many places, not just Google’s store.

Even though Android is very popular, Google has had some trouble making it as big a money maker as they hoped. This is because many phone makers have changed Android a lot, and many people use apps and services that are not Google’s. To help Android grow, Google started making sure phones show the Android logo if they use Google’s special tools.

One big challenge for Android is “fragmentation.” This means there are many different kinds of Android phones, with different hardware and software. This makes it harder for app makers to make programs that work the same on every Android phone. Some say this has helped Android grow because many cheaper phones use older versions, but it can make things harder for app developers.

Market share

Main article: Usage share of operating systems

Android is the biggest phone system in the world, with 76% of the market as of early 2025. It is the most used phone system in many places, like India, where over 96% of phones use Android. On tablets, things are closer, with Apple’s iPad being a bit more common around the world.

When Android started in 2009, it had only 2.8% of the world market. But by 2010, it grew to 10%, passing older systems. By 2011, Android became the top phone system in the world. In the US, it took over in 2011 as well.

By 2012, Android had 75% of the world market for phones. In 2013, over 48 billion apps were downloaded from Google’s store, and one billion Android phones were sold.

Android’s share changes in different places. In the US in 2012, 52% of people used Android, but in China it was 90%. By 2020, Android was the most used system for web browsing, even passing Windows.

On tablets, Android started slow but caught up. Early tablets had trouble because there were not many good apps made just for tablets. But by 2012, with cheaper tablets like the Nexus 7, Android tablets started selling more than iPads.

Platform information

Main article: Android version history

Android has more users than Apple’s iOS on tablets and phones. As of 2026, Android 16 is the most used version on phones, and Android 14 is the most used on tablets. Most people use newer versions that get updates, but some still use older versions that no longer get security fixes.

Application piracy

Paid Android apps used to be easy to copy without paying. Some game makers said most of their players did not pay, but others said only a small part of their players copied apps, mostly in places where Google Play was not available. Google made tools to help stop this, but some makers said they were not enough. Later, Android added ways to protect paid apps better.

Legal issues

Further information: Smartphone patent wars, Patent troll, and Google litigation

Android has faced many legal cases about patents, copyrights, and unfair business practices.

Patent lawsuits

Oracle

Main article: Oracle v. Google

In 2010, Oracle sued Google, saying Android used parts of Java without permission. Oracle wanted a lot of money, but the court said Oracle needed to change its request. Google defended itself, saying Android did not break Oracle’s patents or copyrights. In 2012, a jury agreed that Google did not break Oracle’s patents, but the judge said Google might have broken copyright rules about how Java works. In 2014, a higher court said Oracle was right about the copyright rules. In 2015, Google changed Android to use a different version of Java to avoid these problems. In 2016, a court said Google’s use was allowed. In 2021, the highest court in the United States said Google’s use of Java was allowed.

Android manufacturers

Besides suing Google, some companies sued Android device makers to make it harder and more expensive to sell Android devices. Apple and Microsoft both sued several Android device makers. In 2012, Microsoft said it had deals with many Android device makers, including Samsung and HTC. Microsoft also made some of its apps, like Microsoft Office Mobile and Skype, required on Android devices as part of these deals. Google bought many patents from Motorola Mobility and IBM to protect Android from these lawsuits.

Antitrust

Main article: Antitrust cases against Google by the European Union § Android investigation

In 2013, a group supported by Microsoft and Oracle said Google was being unfair with Android. In 2016, the European Union said Google was being unfair by making device makers include Google’s apps and not allow changes to Android. The EU fined Google €4.3 billion and said Google had to change its ways. Google said it would change how it sells Android in Europe, letting device makers choose different apps. Similar fines happened in Russia, Turkey, South Korea, and India for similar reasons.

Other uses

Google has made different versions of Android for special uses. These include Wear OS for watches, Android TV for televisions, Android Things for smart devices, and Android Automotive for cars. Android can also be used on many other gadgets like laptops, cameras, and even robots.

Android’s flexibility lets companies put it on many kinds of electronics. Some examples are game consoles, home automation systems, and car stereos. In 2011, Google showed how Android could control home devices like lights and thermostats. Even though this idea wasn’t new, Google wanted to bring its services into people’s homes in new ways.

Mascot

The Android mascot is a green robot, which relates to the name of the software. For a long time, it did not have an official name, but Google's Android team called it "Bugdroid." In 2024, a Google blog post gave it the official name, "The Bot."

The robot was designed by Google graphic designer Irina Blok on November 5, 2007, when Android was first announced. Blok said she created it on her own and made it open source. Although the design was not shown to Google at first, it became popular with the Android development team. Because it was free to use under a Creative Commons license, Google finally adopted it as part of the Android logo when the software launched in 2008.