desktop backgrounds onto which all the icons, menus and other elements of the operating system are displayed. Taken from the computer terms section.
It is nice to have a change from the same old boring desktop backgrounds of Windows Xp and Windows Vista. Even though they both come with some great pictures for the desktop backgrounds it is still fun to personalize the look of your computer wallpaper yourself. However I do have to warn you that putting a fantastic looking picture on your desktop as wallpaper can slow some older computers down.