Many types of metadata, serving different purposes, might be associated with a digital object (or subset of objects) in a repository:
Descriptive metadata include content, or "bibliographic," description (including subject access) and possibly content ratings or evaluation information;
Administrative metadata relate to terms and conditions of use, provenance (e.g., original source, date of creation, and version), processing (e.g., file format or internal structure), transactions (e.g., date of deposit or request), and object interrelationships; and
Structural metadata concern information that makes the object usable, for example, to enable page turning in an electronic book.
Work on metadata in specific communities may suggest more, depending on the nature of the object.(n8) Some metadata can be created automatically, but much requires human labor.