A plugin is a source for adding any useful feature to a particular build project like creating documentation and Java code compilation and so on. The Plugin enhances the Gradle features, and it provides an option to customize each and every build. The main job of a Java Plugin is to add Java compilation besides bundling and testing capabilities to the tasks. The plugin is a SourceSet that acts as a collection of source files that you can execute and compile together. Thus, they add original tasks and can build domino and so on.