How to Choose Between an Internal and External Hard Drive
When you're looking to add a new hard drive to your computer, you have the choice of adding an internal hard drive or an external hard drive. Internal hard drives are installed inside your computer, and external hard drives are connected to your computer via USB or Firewire or some similar connection. External hard drives typically have their own case, called an enclosure; this enclosure is what allows the hard drive to connect to your computer's USB or Firewire ports. If you were to open the enclosure, you would probably find a hard drive identical to a typical internal hard drive.