Okay, stay with me here. You could go to anyone, they can format your book and print it out for you. What is the pipeline of publishing look like?
Publishing means putting your work out there for people to buy/read - you could technically just publish yourself on a blog... what matters is do people read and like your work. That aside if you want to trad pub you query agents, if one agrees to represent you they then hopefully get you a deal with a publisher. If you want to self pub you go get your work ready to go then put it out on Amazon, Kobo, B&N, I player, google play etc (or use a service like draft to digital or pronoun), and use create space or ingram spark to put it out as a PoD print book .. which you then market
I believe that the most traditional pipeline, summarized, is: - Write. (And rewrite and edit and get opinions and rewrite and polish, etc., plus presumably further rewrites and polishing in the subsequent stages.) - Submit to agents. - Get agent. - Agent submits book to publishers. - Publisher accepts book. - Publish! - Publisher offers book to booksellers. - Booksellers offer book to people. - People buy book. - People read book. I listed it out to see if I'm demonstrating any deep lack of understanding.
I think you could add a few rounds of "edits" in between "Publisher accepts book" and "Publish", but otherwise that looks about standard.