Since css2, we are using background images. There was a limiitation( in css2 ) that only one image can be used in a single element. Another limitation was that background images with background-repeat:no-repeat are for fixed elements only. For liquid elements like body, background images are full only if screen resolution and image size are same. But CSS3 introduced background size property to overcome this issue.
Various Background Properties
|Background-color||color of background|
|Background-image||url of background image|
|Background-repeat||repeat (default), no-repeat, repeat-x, repeat|
|Background-position|| position of background image, first value for x-axis and second for y-axis,
|Background-size||auto( default), cover, contains Introduced in css3|
|Background-origin||padding-box(default), content-box and border-box Introduced in css3|