This document discusses Gradle and its use in Android Studio. It begins with defining Gradle as a build language, dependency manager, and task scheduler that uses Groovy for a build-by-convention approach. It then notes how Gradle makes it easy to create Android projects with multiple modules and build types/flavors in Android Studio. The rest of the document demonstrates Gradle's project structure and basics, use of plugins and tasks, and how to set up multi-module, build type, and flavor configurations to build different variants of an Android app in Gradle and Android Studio.