"Create bibliography" means "create bibliography node" or "create bibliography entry" or "create publication" --- it doesn't create a new list of publications, but adds a single new publication to this website's database.
The database itself can be viewed in many different ways, e.g., only entries from a given year, author, publication, etc., or only entries with certain keywords or tags. Each of those subsets of the site's publication database might properly be called a separate bibliography, but you get them by clicking on the appropriate links when you're looking at an example publication, not by clicking "create bibliography".
