The background shorthand CSS property sets all background style properties at once, such as color, image, origin and size, or repeat method.
The property is a shorthand that sets the following properties in a single declaration: background-clip, background-color, background-image, background-origin, background-position, background-repeat, background-size, and background-attachment.
As with all shorthand properties, any omitted sub-values will be set to their initial value.
The background property is specified as one or more background layers, separated by commas.
The <bg-size> value may only be included immediately after <position>, separated with the '/' character, like this: "center/80%".
The <box> value may be included zero, one, or two times. If included once, it sets both background-origin and background-clip. If it is included twice, the first occurrence sets background-origin, and the second sets background-clip.
The <background-color> value may only be included in the last layer specified.
The definition of 'background' in that specification. Candidate Recommendation The shorthand property has been extended to support multiple backgrounds and the new background-size, background-origin and background-clip properties.