Power on, POST, and Boot

Power on, POST, and Boot: Which is which?
digraph D {

node [fontname="Helvetica", fontsize="11"] edge [fontname="Helvetica"]

poweron       [label="POWER ON", shape="box", style="bold"] post          [label="POST", shape="box", style="bold"] boot          [label="BOOT", shape="box", style="bold"]

poweron -> post -> boot

}
 * Power on
 * is what happens when the systems first gets electricity. You may hear a beep or a fan or see the lights come on.


 * POST
 * means Power On Self Test and is a basic system check that happens once the system has powered on successfully.


 * Boot
 * means the computer is loading an operating system, typically off of the hard drive (but it also could load the OS off of a floppy, a CD, or even over the network).

If you see a system trying to boot, then you know it must have POSTed. This means that if you see an OS load (i.e. a system boots to Windows or Linux) then the POST was successful. Likewise, if you see a message similar to "Operating System not found" then the boot is failing, but of course this also mean that the system successfully POSTed.

'''NOTE: We never want to boot from an OS. We, however, do want to try to get the system to POST.'''