What is the role and purpose of SourceSets in the development and build process of a project?

SourceSets are a concept in build systems (such as Gradle) that allows organizing the project's source code and resources into different sets.

In Android development, SourceSets help separate code and resources for different build variants, such as debug and release, or for different flavors of the app.

Each SourceSet contains:

• Java/Kotlin source files,
• resources (Android resources, configuration files, etc.),
• manifests.

This makes it easy to manage different versions of code and resources, overriding them for specific build variants without duplicating the entire project.

Example: In a project, there is a 'main' sourceSet with the base code and a 'debug' sourceSet with additional debugging code. When building a debug version, Gradle combines both sets.