Field

Pages to show in the header navigation menu.

Select pages from your Pages. You can reorder them using the sort field. These will appear as menu items in the header.

Selecting Header Links will make your header navigation menu show these links instead of the default selected pages at Settings -> Pages.
The sort order determines the display order in the menu.

Field

Pages to display in the footer "Pages" section.

Select pages from your Pages collection. You can reorder them using the sort field.

Field

Services to display in the footer "Services" section.

Select services from your Services collection. You can reorder them using the sort field.

Field

Projects to display in the footer "Projects" section.

Select projects from your Projects collection. You can reorder them using the sort field.

Don't add too many links to the footer. 5-7 items per section is a good maximum.