POST

POST stands for Power On Self Test. It is a common term for computers, printers and routers. They define these devices' pre boot sequence. On almost all the computer structures available, you will find almost the same boot sequence.

POST is the first process of BOOTING of a computer. On starting up the PC, the general functions of POST are carried on by the BIOS. POST in itself . These include finding the main memory, and verifying its size; detect and initialize all system buses; pass control to other system BIOSs if required; provides an interface for configuration of the system by the user and construction of an environment for system booting by integrating various bootable devices.

The main BIOS is divided into two sections, the POST code and the the RUNTIME code. The POST code is useful for performing the functions I mentioned above. The second part or the RUNTIME code is used to transfer control to the operating system. In very general terms and to oversimplify things, the POST code must be flushed out before initializing the RUNTIME code.

The POST runs very quickly and most of the time you will not even notice it running, till it encounters a problem and reports it to you. You may come across PCs that would make a beeping sound when you start them up. This is the POST telling you that not everything in your PC is in order. These beep patterns can be used to identify different hardware problems in the hardware of your PC.