Android was designed and built by Google in 2008. The operating system is written mainly in Java, with core components in C and C++. It is built on top of the Linux kernel, giving it incorporated security benefits.
Android is a mobile operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen-based mobile devices such as smartphones and tablets. Android has historically been developed by a consortium of developers known as the Open Handset Alliance, but its most widely used version is primarily developed by Google. First released in 2008, Android is the world's most widely used operating system; the latest version, released on October 15, 2024, is Android 15.
At its core, the operating system is known as the Android Open Source Project (AOSP) and is free and open-source software (FOSS) primarily licensed under the Apache License. However, most devices run the proprietary Android version developed by Google, which ships with additional proprietary closed-source software pre-installed, most notably Google Mobile Services (GMS), which includes core apps such as Google Chrome, the digital distribution platform Google Play, and the associated Google Play Services development platform. Firebase Cloud Messaging is used for push notifications. While AOSP is free, the "Android" name and logo are trademarks of Google, who restrict the use of Android branding on "uncertified" products. The majority of smartphones based on AOSP run Google's ecosystem—which is known simply as Android—some with vendor-customized user interfaces and software suites, for example One UI. Numerous other distributions exist, both commercial and community-developed, which include Amazon Fire OS, Oppo ColorOS, LineageOS, amongst others; the source code has also been used to develop a variety of Android distributions on a range of other electronics, such as Android TV for televisions, Wear OS for wearables, and Meta Horizon OS for VR headsets.
Software packages on Android, which use the APK format, are generally distributed through proprietary application stores like Google Play Store, Amazon Appstore, Samsung Galaxy Store, Huawei AppGallery, Cafe Bazaar, GetJar, and Aptoide, or open source platforms like F-Droid. Since 2011 Android has been the most used operating system worldwide on smartphones. It has the largest installed base of any operating system in the world with over three billion monthly active users and accounting for 46% of the global operating system market.