BackgroundField started as an extension of the CCK ImageField that allows a CSS selector and background attributes to be set for a content-type. This is particularly helpful for allowing your node authors to add images to a node that are integrated into the theme of the site. With the inclusion of the Image field in Drupal 7, BackgroundField was rewritten to extend that core functionality.
User A creates content-type Foo with 2 BackgroundFields, one with a CSS selector for "body" (the html body) and one for "#callout" (a div in the theme).
User B can then create a Foo node and add images that will become the body background image and the callout background.
Users could continue to create new nodes each specifying their own background and callout images unique to the node they create.
Drupal 6.x Requirements
The Drupal 6 version is only updated for maintenance fixes.
Drupal 7.x Requirements
- Image (core module)
The Drupal 7 version is being actively developed.
Note: If you only need the ability to set one theme background via the drupal admin interface, you might consider the Background module.