Generally, a genealogical DNA test might use either autosomal STRs or autosomal SNPs. (STR's are Short Tandem Repeats; SNPs are single-nucleotide polymorphisms.) However, testing companies do not currently offer autosomal STRs tests that use enough STR markers for genealogy.
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.
Active Directory uses objects to store and reference data in the directory. The schema defines the types of objects that are available to the directory service. The schema is stored in the schema partition, which is also defined as an object in the directory.