keyboard
The keyboard, usually combined with the computer is one of the most important external device as it allows the input of letters, numbers and symbols to your computer. This is essential for almost every purpose of the computer. Whether it be typing documents or playing games, the keyboard is essential for the computer. It also has the function of shortcuts such as the well known "Ctrl+Alt+Delete". Using the command prompt, you can also enter manual instructions you want the computer to do by typing it in using the keyboard.
References: http://en.wikipedia.org/wiki/Computer_keyboard
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/win_kbd_overview.mspx?mfr=true
http://publib.boulder.ibm.com/infocenter/cmod/v8r3m0/index.jsp?topic=%2Fcom.ibm.ondemand.mp.doc%2Farsc0218.htm
References: http://en.wikipedia.org/wiki/Computer_keyboard
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/win_kbd_overview.mspx?mfr=true
http://publib.boulder.ibm.com/infocenter/cmod/v8r3m0/index.jsp?topic=%2Fcom.ibm.ondemand.mp.doc%2Farsc0218.htm