Deadlocks and metadata locks

I have a deadlock situation that I am having some difficulty understanding. Attached is the deadlock graph - I am trying to understand why we see so many metadata locks. Is a metadata lock the same as a Schema lock ? I think not, but the Object ID in the matadata lock actually belongs to a user table(not system tables/management views).

I would appreciate any insights anyone may have as to what exactly a metadata lock is and why does SQL Server use them in my context ? We are not referencingany system objects / views etc.