So I was unfamiliar with this term and found this:
In engineering and its various subdisciplines, acceptance testing is a test conducted to determine if the requirements of a specification or contract are met.
In software testing the ISTQB defines acceptance as: formal testing with respect to user needs, requirements, and business processes conducted to determine whether a system satisfies the acceptance criteria and to enable the user, customers or other authorized entity to determine whether or not to accept the system.
Wikipedia, Acceptance Testing