What is user acceptance testing (UAT)?

User acceptance testing (UAT) is fundamentally the phase in a software development lifecycle where actual end-users evaluate the software to determine if it meets their needs and requirements. This phase is crucial because it ensures that the product not only fulfills technical specifications but also aligns with the expectations of its intended audience.

During UAT, users will interact with the application in a real-world scenario, simulating how they would utilize the software in their day-to-day tasks. This hands-on approach allows users to identify any discrepancies between their requirements and what has been delivered, providing the team with valuable feedback for final adjustments.

In contrast, the other options describe different phases or aspects of the software development process that do not focus on user involvement in the testing stage. Automated tools are typically used in earlier testing phases, integration focuses on bringing various software components together, and initial testing is often conducted by developers to ensure that the code is functional before it even reaches the user.