Besides entering characters, computer keyboards also have special keys that change the symbol (such as shift or caps lock) or give the computer special commands (such as the arrow keys, CTRL and ALT). Different computer operating systems use different special keys, or use them differently. Special commands can also be activated through combinations of keys, called keyboard shortcuts. Some of the most common shortcuts on Windows programs are: Ctrl + C, to copy some text or a picture; Ctrl + V, to paste what was copied; and Ctrl + F, to find a certain word on a document or webpage.