You might have noticed that you can pretty much edit anything in this space. This is because the space is in what's know as live edit mode. In this mode, anyone who has permission can edit the content directly. This is great for early-days use. It is great for quick changes. No need for complex workflows.
At some point, you may reach a greater level of maturity with your content. That's when you may need some of the more powerful workflow features in GitBook…
The alternative to a live edit mode is called locked edits. Spaces that are locked for live edits aren't directly editable, and any edits you need to make must be handled through change requests. You can lock a space using the space menu and selecting 'Lock live edits'.