POST, or Power On Self Test, is a series of tests that a computer goes through to check that all the systems are functioning properly. Computer systems perform a POST every time the computer boots up.
What Does POST Do?
It checks that the hardware of the system, such as the CPU/Processor, RAM, storage devices, graphics cards and other hardware devices are working properly.
What Happens If The System Fails POST?
If it fails POST, it means that something is wrong with the hardware of the computer. On some motherboards, there is a POST Information Screen. When the system fails POST, it will display a number, which will tell you what hardware is broken (These numbers vary by motherboard)
Macs (All Macs)
When Macs fail POST, it will usually show a icon (Example: Question Mark Folder Icon) to signify what system is broken. Usually, when Macs don’t boot, you will have to take it to a Apple Store or a repair shop.
Is POST Used As A Verb?
Computer enthusiasts and professionals usually use POST as a verb. For example when a computer goes through POST, they will say “Yes! The PC posted!”