What is a signature request in Dropbox Sign?

A signature request is when you prepare a document, send it out for someone to sign, and collect it back using Dropbox Sign.

The term "signature request" refers to the entire document transaction.  You can have as many signers add their signature as many times as necessary to as many documents as you need to upload.  As long as you send the documents out together in a single bundle, all at once, it will count as one single signature request.