If you’ve ever had a chance to build a ROM from source, no matter if it was AOSP or some other distribution, you might have noticed that the source tree has a lot of folders. Some of them are responsible for keeping device-specific parts, while others are used to coordinate the whole process of building.
If you ever wanted to know what is kept inside of these mysterious folders, you should definitely read a guide written by XDA Senior Member #Superuser. The folder structure will no longer be a mystery, as most folders are described. #Superuser also described the build-specific parts to help you better understand the process of inheriting the source on various configs.
Folder structure isn’t all that’s covered in this guide. Basic build commands are also presented in detail, so even beginners can find something to read about. Every moment is good to learn something new, so if you use Linux or Mac, you should definitely try to build a ROM from source and analyze the folders.
If you are new to the development world, you should definitely give this guide a shot. The best thing you can do is to visit the original thread and read it carefully while syncing source.