system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does it take so long to close a frozen program with "End Task" in task manager, yet killing a process is instantaneous?
gpt
End Task relies on sending a signal to the program telling it to die. That requires the program to respond and terminate, which it wont if it's really stuck. After some time the option to try and force close is made available.

Killing a process just outright stops giving it resources so it instantly is removed from the process tree, stops calculating, etc.

It's preferable to have the program kill itself where possible so it can perform any needed cleanup, but sometimes a program is so stuck it can't.