Switches are similar to hubs, but they not only provide a central distribution point, but they also "switch" the information.  That is they open up the packet, look at the destination, and send it down whichever branch the destination computer is on.

A Switch is a network device that filters, forwards, and floods frames based on the destination address of each frame. The switch operates at the data link layer of the OSI model.

Below are a few sites that give definitions and brief descriptions of switches:

• What Is a Switch

• Switch according to the Web-Encyclopedia

Here are some sites that give more information about switches:

• Switches 1 (Cisco)

• Switches 2 (Cisco) 

• Switches 3 (Cisco)

• Switches 4 (3Com)

• Layer 3 Switches (3Com)

• 3Com Switch Architecture

• Ericsson's Data Link Switching

Here are some companies that deal in switches:

• Cisco

• Nortel

• 3Com

• GDS

• Global Data Systems

• Ericsson