What does boot override in the BIOS actually do?

[JohnD77]

In the boot section of my BIOS there is something called "boot override" and under that are all my bootable devices. Every time I select any of them, I see the computer sort of trying to boot from whichever option I choose and then go back to the BIOS where I left off. I don't understand what happens when I do that and what the point of doing it is.

 

[pauls3743]

Scenario

You current boot order is OS drive first, it's set at this this to give you the quickest boot time as it skips trying to boot from the optical drive and usb flash drives, or any other hard drive for that matter.
You get a problem and you decide to check the RAM using memtest 86.
This involves burning an ISO to an optical disc and then booting to it.
You insert that disc into the optical drive and find you can't boot to it because your boot order is optimized for boot speed (skips optical drive)
This is where "boot override" comes.
This allows to boot from that optical drive this one time without having to reassert your quick boot order for future boots.

You can also use it to install operating systems and test Linux live discs.

 

[JohnD77]

Scenario

You current boot order is OS drive first, it's set at this this to give you the quickest boot time as it skips trying to boot from the optical drive and usb flash drives, or any other hard drive for that matter.
You get a problem and you decide to check the RAM using memtest 86.
This involves burning an ISO to an optical disc and then booting to it.
You insert that disc into the optical drive and find you can't boot to it because your boot order is optimized for boot speed (skips optical drive)
This is where "boot override" comes.
This allows to boot from that optical drive this one time without having to reassert your quick boot order for future boots.

You can also use it to install operating systems and test Linux live discs.

So basically it changes the boot order for one boot instance? meaning that while I'm in the BIOS, if I choose the optical drive, it's gonna stay as 1st in my boot order while I stay in BIOS and as soon as I exit the BIOS and bootup beggins, I will boot from the optical drive and the BIOS settings will be reverted automatically making my HDD 1st in boot order again?

 

[pauls3743]

That's pretty much it.