1976
Apparently, Google's new AI-based search is quite honest.
(sh.itjust.works)
This is a most excellent place for technology news and articles.
More specifically kill normally sends a SIGTERM which is the equivalent of clicking the X button in Windows. It's a polite request that the program close itself. Signal 9, also known as SIGKILL shuts the program down immediately and is the equivalent in Windows of opening the task manager and pushing the end process button. It terminates the program immediately without giving it any time to do anything it might still have pending, but in the event that the program is unresponsive might be the only way to successfully close it.
TIL. And thanks for the Windows analogues. I like learning about stuff like this.