Official Description: The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later.

CommonsWare’s Notes

This library contains a backport of the deprecated framework implementation of the Loader framework. Added back in API Level 11, loaders were envisioned as a general-purpose solution for lifecycle-aware data loading for activities and fragments. As it turned out, Loader had design issues. And the overall approaches for asynchronous data loading have changed in the intervening years (RxJava, coroutines, LiveData, etc.). As a result, this library exists mostly to support developers who invested in Loader and need to keep using it despite the deprecation of the framework implementation.