Acceptance Criteria :
These are basically a set of rules or requirements given by the Stakeholders which are to be met in order to accept the user story in terms of agile or any output or solution to be complete or to be considered acceptable to the client or stakeholders.
They are usually defined initially in SDLC process and must be met (Yes Or No) in order to say that a software is complete, correct & good to be implemented.
These are a set of requirements which are used to select between multiple output to a certain problem. In this each output are given scores in order to examine & evaluate for consideration.
These outputs are being evaluated based on priorities & importance, then each output are scored & the ones which are of less score or doesn’t meet or justifies the requirements are been removed from the consideration list.