Macintosh startup

Common card · No. 298272

The startup sequence for Apple's Macintosh (or Mac) computers includes hardware tests and diagnostics which can trigger the startup chimes, or other instances of success or failure or both of the startup routines. The startup sequence provides auditory and visual symbols of the computer's status and condition as it powers up, providing users with immediate feedback on the machine's soundness. Additionally, they allow the user to quickly identify any potential problems and take any appropriate actions to rectify faults.

Read on Wikipedia