Signer is anyone who signs a document on ZapSign (it is not necessary to have an account or registration to sign documents).
User is who you invite to enter your account and be able to create documents with you (eg collaborators, employees, co-workers).
All paid plans have an unlimited number of signatories, both at the account and document level. ZapSign only limits the number of users on your account as per your plan. Click here to compare plans.