Almost everything in GitBook revolves around a space. What you're looking at right now is a space (well, technically, it's some words inside a content block inside a page inside a space, but let's not get too fancy) and it's basically a collection of pages.
Folks use spaces for all kinds of things. You might want to create API documentation, a design system, a place to document calls and meetings. Whatever it might be, chances are, you'll be using spaces a bunch in GitBook.
Spaces can be published to the whole world, or just some of it, or just to a few very specific people. You can also invite folks to collaborate with you on a space if you're on a community, team, or business plan.
There's tonnes you can do with Spaces, and you'll definitely figure them out over time, but for now, let's move on to collections…