What does POST stand for?

POST stands for Power On Self Test. This is a diagnostic process that a computer's firmware performs when the system is powered on. During this test, the computer's hardware is checked to ensure that essential components, such as the processor, memory, and disk drives, are functioning correctly. If the POST encounters an issue, it will usually signal this through a series of beeps or error codes, allowing users or technicians to troubleshoot hardware problems.

The other options do not accurately reflect the standard definition of POST within the context of computer systems. For instance, while terms like "Power On System Test" or "Preliminary Operating System Test" might seem related, they do not represent the established terminology used in computing to describe this crucial diagnostic process. The "Process of System Testing" option does not appropriately capture the specific function and purpose of the POST as it relates to initial hardware diagnostics upon startup.