What are the binary files associated with Active Directory?

The schema is the Active Directory component that defines all the objects and attributes that the directory service uses to store data. The physical structure of the schema consists of the object definitions. The schema itself is stored in the directory.

The schema is stored in its own partition (the schema partition) in the directory. The schema is replicated among all the domain controllers in the forest, and any change that is made to the schema is replicated to every domain controller in the forest. Because the schema dictates how information is stored, and because any changes that are made to the schema affect every domain controller, changes to the schema should be made only when necessary — through a tightly controlled process — after testing has been performed to ensure that there will be no adverse effects on the rest of the forest.