User acceptance testing (UAT) is a critical phase in the software development lifecycle where the end users evaluate and validate a system to ensure that it meets their requirements and expectations before it is deployed into production. (See also Beta testing). 

The primary goal of UAT is to confirm that the software behaves as intended and that it satisfies the business needs for which it was developed.

The key aspects and importance of UAT

• End-user validation. UAT involves actual end users of the software interacting with the system to perform real-world scenarios and tasks. This allows users to validate whether the system meets their expectations and whether it aligns with their workflow or business processes.
• Identification of defects and issues. UAT helps in identifying any defects, bugs, or issues that may not have been detected during earlier stages of testing. Users provide valuable feedback on functionality, usability, and any discrepancies between the system and their requirements.
• Risk mitigation. By involving end users in the testing process, UAT helps mitigate the risk of deploying a system that does not meet user needs or fails to perform as expected in a production environment. An app or system that does not satisfy users is ultimately a financial failure.
• Enhanced communication. UAT fosters communication and collaboration between the development team and end users. It provides a platform for users to express their concerns, preferences, and requirements directly to the development team, facilitating better understanding and alignment.
• Regulatory compliance. In certain industries, regulatory compliance is crucial. UAT ensures that the software complies with relevant regulations and standards of its target market before it is released into a production environment.