I always wondered a few things with Ok/Okay. In Spanish we commonly use it as "ok" and it's to agree in something, like saying "de acuerdo" (agree), but in English is used as "okay" and it's to agree with something and also when someone asks you how are you, you can reply with okay as fine.

As for the story behind the word, once (when I didn’t want to know everything) I read that O.K. came to existence because during war times if the trope came back to the base without any death they wrote on a board 0.K. meaning 0 Kills, this morning I decided to check and… IT WAS ALL LIES!!! I lived in ignorance for many years!!! Good that I never repeated that information to someone else.

And yes, you are right, don't trust in Google, it lies.

De nada ¡Siempre a la orden! :)