- Site Title & Tagline
- Header Image
- Background Image
- Static Front Page
Apart from two last items, Navigation and Static Front Page, which are better dealt with separately, the function of these menus is simple and self-evident.
While they are gathered here for quick access, this is by no means EVERYTHING you can do to customize your site. Moreover, all of these settings can be changed elsewhere, with additional options, in other Dashboard menus.
The big blue button, then, is handy for certain things, but very limited.