"Copies of documents" vs. "copy of documents"

What is the grammatical difference between "copies of documents" and "copy of documents"?

Same applies to other nouns. Also, an example will be very much appreciated.


"Copies of documents" implies multiple copies of a batch or batches of documents. It isn't very clear if they mean one set of documents or multiple sets all copied multiple times.

"Copy of documents" is a bit clearer and implies a single copy of one batch of documents.