Android API Level 21
Android API Level 21, also known as Android 5.0 Lollipop, is a specific version of the Android operating system's application programming interface (API) that defines the set of features, capabilities, and system behaviors available to developers. It introduced major changes like Material Design, improved performance with the Android Runtime (ART), and new APIs for notifications, camera, and battery usage. Developers target this API level to ensure their apps are compatible with devices running Android 5.0 and later, while also leveraging its modern features.
Developers should learn and use Android API Level 21 when building apps that need to support older devices while incorporating modern Android features, as it marks a significant upgrade from earlier versions with improved user experience and performance. It is essential for apps requiring Material Design aesthetics, enhanced notifications, or better battery management, and it serves as a baseline for many apps to maintain compatibility with a broad range of Android devices. Use cases include developing consumer apps that target a wide audience or updating legacy apps to include newer functionalities without dropping support for older Android versions.