Abbreviated as POST, the Power On Self Test is the initial set of diagnostic tests performed by the computer when powered on.
Tests that fail are relayed to the user via the use of POST codes, beep codes or on-screen POST error messages immediately after the computer powers on.
The POST is handled by the system's BIOS.
Also Known As: POST
Examples: After I upgraded the memory in my computer, the POST generated a series of short beeps. After troubleshooting the problem, I discovered that I had not pushed the memory firmly enough into the slot on the motherboard.