Android is the operating system developed by Google for mobile devices. It is based on a modified Linux kernel and was designed primarily for smartphones and tablets, although it now powers many other types of connected hardware.
Android began with Android Inc., a startup founded in 2003 by Andy Rubin, Rich Miner, Nick Sears, and Chris White. Google acquired Android Inc. in 2005 and helped turn the project into a broad mobile platform. The first commercial Android phone, the HTC Dream—also sold as the T-Mobile G1—was released in 2008.
The Android Open Source Project provides the platform’s core code, allowing manufacturers and developers to adapt it. However, many consumer devices also include proprietary Google Mobile Services, including Google Play and Google Maps. Those services are separate from the open-source core, which is why Android versions can differ between manufacturers.
A common mix-up is treating Android as identical to Google’s app package. Android is the operating system; Google Play, Chrome, and other Google apps are additional software often bundled with it. Tizen and iOS are separate platforms.