User Acceptance Testing (UAT) is a crucial part of the software development lifecycle. It is typically one of the final testing phases that checks the functionality of the software from the users' perspective. UAT focuses on validating the end-to-end business process, including user interactions, and confirming that the software meets its intended usage in a real-world scenario. It helps identify bugs or issues before the final version is released to ensure that the users can efficiently and effectively use the system.