There are a variety of different methods of connecting two computing devices together. Here are the most common ones.

Universal Serial Bus (USB)

An external bus standard that supports data transfer rates of 12 Mbps (USB 2.0 allows for transfer speeds of up to 480 Mbps). A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards. USB also supports Plug-and-Play installation and hot plugging.

IEEE 1394 (Firewire)

A very fast external bus standard that supports data transfer rates of up to 400Mbps (in 1394a) and 800Mbps (in 1394b). Products supporting the 1394 standard go under different names, depending on the company. Apple, which originally developed the technology, uses the trademarked name FireWire.