- PC HARDWARE -

A "peripheral" is a hardware device that you plug into to your PC like a printer, camera, scanner, sound system, etc.  In a sense, things like your monitor, keyboard, and mouse are also "peripherals" - but without them your PC itself won't function - so I like to think of them as part of your "base unit" .   

A peripheral plugs into a connector on the back (or front) of your PC called a "port".  The four most common ports on today's PCs are "parallel" ports (for your printer), "serial" ports (for your mouse, external modem, or "palm-pilot"), PS-2 ports (for mice and keyboards on an ATX motherboard), and USB ("universal serial bus" ports which are becoming very common for all peripheral devices).  There are also "infrared" ports and devices starting to appear on the market.

To make a peripheral work properly, you need a software `driver' that lets your PC `talk' to the external device.  Windows 95, 98, 2000, ME, NT, and the XP family come with a lot of these drivers built in (for their "plug-and-play functionality) but newer hardware needs drivers provided by the equipment manufacturer.  Most peripheral drivers, if you don't have them, can be downloaded from the manufacturers web site.