The term identifies a specific version of the Android operating system and its corresponding application package file format. This iteration of the Android OS, released in 2009, marked a significant advancement in mobile technology. The application package file, signified by the “.apk” extension, is the standard format used for distributing and installing applications on devices running this operating system.
This particular release was important because it introduced key features that enhanced the user experience and expanded the capabilities of Android devices. This included support for multiple Google accounts, Exchange email, and a revamped browser. Its historical context is significant as it laid the groundwork for subsequent Android versions, influencing the evolution of mobile app development and functionality.