POST may refer to any of the following:
1. Short for power-on self-test, the POST is a test the computer must complete verifying all hardware is working properly before starting the remainder of the boot process. The POST process checks computer hardware, like RAM (random access memory), hard drive, CD-ROM drive, keyboard, etc., to make sure all are working correctly.
If all hardware passes the POST, the computer continues the boot up process and may generate a single beep sound as well. If POST is unsuccessful, it generates a beep code to indicate the error encountered and the computer will not boot up. All POST errors are relating to hardware issues with one of the components in the computer.
2. When referring to a message board, comment section, or social network, a post is a message, such as text or images, published online by a user. "To post" is also a verb, meaning to publish a message. For instance, "You can click here to post this message," or, "Many forum users are posting frequently."
For example, you can post a message on your Facebook page to tell your family and friends what you did on a vacation. You can also post a status update to tell others what you are doing at that moment.