In software testing, the acronym UAT stands for "User Acceptance Testing." UAT is a critical phase where actual users test the software to ensure it meets their needs and requirements. This testing is often performed after system testing and is crucial for validating that the product is ready for deployment. Through UAT, users can identify any issues or provide feedback on usability and functionality, ensuring that the product aligns with user expectations. Successful UAT is essential for project approval and successful implementation.