Divorce questions.

I'm in canada if that makes a difference to the question asked....but if someone is wanting a divorce and they go to a lawyer, pay the fee to retain the services, and the lawyer says "give me a few business days to draw up the paperwork"

What are they drawing up? Like a document to start the divorce? Or is it the paperwork that they serve the other party (the ex spouse?) Is it like an offer of who gets what and what gets split?

And after they draw up this paperwork, when does the divorce actually happen?

As you probably can tell this is not about me personally. Seeing as I'm clueless here. Just wondering.