This web-presentation is organized like a book. You'll get the most out of it by going through it in a similar manner: from beginning to end.
Carrying on with the book topology, the page is the same a book cover.
Next, is the page (hint, you are on it now). From here, those spacey links, (in the table above) can take you to specific entries.
An catalog provides a mind boggling, contact-sheet (a term from the prehistoric times of non-digital photography) array of thumbnail links to each photo used in this presentation. It's provided as: a convenience, to jog memory of where you may have left off reading the entries, or as way to look at an awful lot of pretty pictures without actually reading anything.
These stunningly beautiful, navigation menu-bars (floating gracefully above the bottom of each page) take you sequentially through the presentation. They always know where you are, and exactly where to go next.
Here's a typical ENTRY with an explanation of it's various parts.