The underlying concept for object identifiers is a tree-structure.
Every node is administered by some authority.
Optionally a name to be associated with the arc for use by human beings, and again providing identification within the arcs from the current node. The root authority in ASN.1 is the ASN.1 standardising body. Each authority, once it has a node on the tree can decide how to administer and divide up its own subtree - within the rules of the format. All rights reserved.