Support for Android
When developing apps that support multiple API versions, you may want a standard way to provide newer features on earlier versions of Android or gracefully fall back to equivalent functionality. Rather than building code to handle earlier versions of the platform, you can leverage these libraries to provide that compatibility layer. In addition, the Support Libraries provide additional convenience classes and features not available in the standard Framework API for easier development and support across more devices.
Originally a single binary library for apps, the Android Support Library has evolved into a suite of libraries for app development. Many of these libraries are now a strongly recommended, if not essential, part of app development.
This document provides an overview of the support library to help you understand its components and how to use it effectively in your app.