There are a couple options for the header background area on your homepage and subpages:

The page "Header Image" field populates the static header background image.  

The page title will display across the header image as an overlay, while the (optional) page description will display beneath the title in smaller text.

The header text field can be used to add text over top of a header image or background video. The amount of content here can vary, but make sure to check any updates/changes on mobile devices as well as desktop, to ensure a good user experience.

Using the field "Header Video" will replace the background image with a background video. The video must be MP4/h.264 formatted video and should use the standard HD ratio of 16:9.

*NOTE - This is a looping/muted background video so the video should be kept short in size/length (recommended under 30 seconds).

If a rotator is assigned to a page, the images will display as slides.  The rotator images are managed under Media > Rotators. The "Title" and "Caption" fields are optional and will display as an overlay. The "Link" field can also be used to add a link to each image.