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

The page "Header Image" field populates the static header background image.  If a header video is present, this image will be the preview image while the video is loading and also serves as the fallback for mobile devices.

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.

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.