A System Test is a type of software testing that evaluates the complete and integrated software system to ensure it meets specified requirements. This testing phase occurs after unit and integration testing and focuses on the overall functionality, performance, and reliability of the software. It simulates real-world usage to identify any defects or issues before the software is released to users. During a System Test, various components of the software, including user interfaces, APIs, and databases, are tested together. Testers use predefined test cases to verify that the system behaves as expected under different conditions. Successful completion of system testing is crucial for ensuring the quality of the software product before it reaches the end-users.