External hard drive

An external hard drive is a hard drive in an enclosure that connects to a computer through a USB or FireWire connection. The enclosure protects the drive from the forces of nature (and spillage) as well as houses the electronics necessary to inferface with the drive. They're especially useful for expanding the amount of storage available on your laptop, or if you're planning on sharing huge amounts of information between computers. For instance, you can move all your .mp3s to an external hard drive and be able to access your music from any computer, even if you don't have an .mp3 player or your collection is too big to fit onto one.

Buying an external hard drive: Option 1 (The easy way)

You can buy one from pretty much any store or website that sells electronics (Wal-Mart even carries one). A cheaper hard drive simply won't function as well, so make sure you buy from a reputable manufacturer like Seagate or Maxtor. Newegg and Outpost (the Fry's Electronics website) periodically have great sales on external hard drives, so check them out if you're in the market.

Buying an external hard drive: Option 2

If you want it is possible to convert a standard internal hard drive to an external hard drive by buying an enclosure and putting the hard drive into it yourself. Why would you want to do this? If you already have an extra hard drive around (from an old computer or such), you can simply buy an enclosure and make it into an external drive. It is also frequently cheaper to buy a drive and enclosure and do the assembly yourself than to buy one that is pre-assembled. Hard drive enclosures usually cost between $20 and $40, depending on what features you want.