What is "user acceptance testing (UAT)"?

User acceptance testing (UAT) is fundamentally a final testing phase in which end users or stakeholders validate the software to ensure it meets their requirements and is ready for production. This phase occurs after all earlier testing has been completed, including unit testing, integration testing, and system testing. During UAT, real users test the software in a real-world scenario to evaluate its functionality, usability, and compliance with business needs.

The main goal of UAT is to confirm that the product behaves as expected in the environment it is intended to be used. It acts as a safeguard to ensure that any issues from the user's perspective are identified and addressed before the software is released.

This focus on user validation distinguishes UAT from other types of testing, such as performance testing, which primarily looks at how well the software performs under certain loads, or developer testing where developers check their own code. UAT is crucial for achieving stakeholder satisfaction and ensuring that the delivered product will solve the business problems it was designed to address.