eli5: How does “restart” work? when a device, e.g. windows PC is turned off, how does in know to turn itself back on?

Question

Edit: Typo in title🤦‍♀️

How does it* know to turn itself back on?

In: 114

Answer 1

When your computer shuts down, it first does a whole cleanup process involving closing all programs, shutting down the network connection, clearing cached disc writes, disconnecting from peripherals, etc. Then, it sends a signal to cut power to the system.

For a restart, it basically does the same thing, except instead of cutting power, it sends a signal to reset the system. This “reset” essentially tells the motherboard to reset all of the components on it such as the CPU and RAM (which generally involves triggering certain pins on these components), and then act like it was just turned on. **But the motherboard itself never loses power in this process.**