The terms wallpaper and desktop picture refer to an image used as a background on a computer screen, usually for the desktop of a graphical user interface. 'Wallpaper' is the term used in Microsoft Windows, while the Mac OS avoids mixing metaphors by calling it a 'desktop picture' (prior to Mac OS X, the term desktop pattern was used to refer to a small pattern that was repeated to fill the screen).

Instructions
There's one more thing you might want to do with your wallpaper - stretch it to fit your screen. The wallpaper photos on this website measure 800 x 600 pixels. Of course there's no way for me to know what size your screen is, and the size of screens keeps increasing anyway. But it doesn't matter, because Windows can take any size of picture and change its size to properly fit the screen, by adjusting your display properties. It's pretty simple - just minimize all of the windows on your PC, right-click on any empty part of the background, and choose "properties". If you're running Windows, click the "display" pull-down menu on the "background" tab, and choose "stretch". If you're using Windows NT similar, go to the "Plus" tab of the properties window and click the checkbox labelled "stretch desktop wallpaper to fit the screen".