Circuit Testing is a process used to verify the functionality and performance of electronic circuits. It involves applying specific signals to the circuit and measuring the output to ensure it meets design specifications. This testing helps identify any faults or issues that may affect the circuit's operation. There are various methods of Circuit Testing, including Functional Testing, In-Circuit Testing, and Boundary Scan Testing. Each method serves a different purpose, such as checking individual components or assessing the overall performance of the circuit. Effective circuit testing is crucial for ensuring reliability in electronic devices.