system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do computers remember to turn back on when you click the restart button in your OS and it shuts off?

If the title was too complicated:

When you click the restart button on, say, the start menu, how does it turn back on if it has to shut down and lose all power and memory first?
gpt
It doesn't completely power off, basically. You know how when you first start your PC from complete power off, and you see the BIOS? Then the windows logo? When you restart, the computer shuts down windows, but doesn't completely turn off the motherboard, which is why the BIOS only shows very briefly during a restart. 

TL:DR; Shuts down windows, doesn't fully turn off motherboard. 

Note: Not 100% accurate with the terms, but close enough for ELI5.