I have been a QE for 4 years in a product company that follows waterfall methodology. I am trying to understand how and when UAT is performed in an agile methodology? I know, agile testers use the acceptance criterias of user stories to frame the test cases. But, isn't the acceptance criterias also help to frame the acceptance tests? Then what is the difference between SIT test cases and UAT test cases in agile? Can anyone please clarify my confusion. Thanks!