OpenTDF
Mojave uses the OpenTDF standard for file encryption and access control. This allows files to be encrypted at rest and safely replicated by anyone regardless of their role in the Mojave network. Validators are responsible for distributing DEKs to actors that have a right to request them. This gives actors the ability to decrypt the content they are entitled to.
NanoTDF and OpenTDF
NanoTDF and OpenTDF are similar formats of the same standard. NanoTDF requires an external resolver to be used to resolve the DEKs. OpenTDF is self-contained and does not require an external resolver. The former is used for most types of content consumption such as streaming while the latter is used for complete ownership akin to a vinyl record.