What does "Fuck Off" mean?

There is figurative, then there is literal. When you tell someone to "Fuck off"....what does that even really mean? To "fuck off"? I know what "jack off" means. But as far as copulation or coitus?

Fucking "off"...it makes no sense. Copulation off? Fuck you? I want to fuck you? If you're mad at someone, why would you want to fuck them? I mean you don't like them....sex is the last thing on your mind. Getting away from them is....but stripping down if they say "Fuck you"? Never happens.

And how about "Fuck it"? Fuck what? As in...fucking chair leg broke. You're not going to fuck the fucking broken leg on the fucking chair right? I mean Holy Fuck.

                                            Here's some fucking memes for you. Fuck it.  :)