Use peripheral devices. Every peripheral that's part of a computer system uses one of the data buses to communicate with the CPU. As long as your system supports a particular data bus, you can add devices that also use that bus.

For example, you can plug an IDE-compatible tape drive into your computer's IDE controller slot, or put a PCI-compatible graphics card into your system's PCI slot.

Add multiple external components. The SCSI data bus is designed to allow you to add multiple devices to your system through a single connection. You just plug in the first SCSI peripheral -- such as an external hard drive -- into the computer's SCSI port, then plug the next device -- a printer, for example -- into the external hard drive, and so on.

Take advantage of "Plug & Play" features. If your system supports PCI expansion ports, you can avoid the hassles of configuring devices and finding software drivers for the components you want to connect to your computer. Plug & Play allows you to connect a PCI-compatible component -- like a video card -- into your system and watch the operating system configure the new card for you.