There are two types of memory volatile and non-volatile. Volatile means that it gets erased if it loses power and non-volatile means it stays if it loses power.
When your computer loads a program it loads it into volatile memory as it's a lot faster to access and make changes to. However, because it's making changes to it, it might do something weird that causes the program to mess up to either that specific program or something else that interacts with it.
By "turning it off and on again" you reset all of the volatile memory and reset it to its initial state, before it caused that issue for itself.
IHOP_007 t1_jdi8pmo wrote
Reply to ELI5: Why does "turning it off and on again" work so well for troubleshooting? by WillShelbyOBE
There are two types of memory volatile and non-volatile. Volatile means that it gets erased if it loses power and non-volatile means it stays if it loses power.
When your computer loads a program it loads it into volatile memory as it's a lot faster to access and make changes to. However, because it's making changes to it, it might do something weird that causes the program to mess up to either that specific program or something else that interacts with it.
By "turning it off and on again" you reset all of the volatile memory and reset it to its initial state, before it caused that issue for itself.