Hub - basically just sends all information to all computers. On a 100Mb/s connection, 2 computers will have 100Mb/s. With 3 computers, it'll drop to 33.3Mb/s, with 4 computers, it'll drop to 25Mb/s, with 5, 20Mb/s, etc.
Switch - Only sends the information where it's supposed to go, so the bandwidth isn't shared. This gives 100Mb/s performance to all computers on the network.
Router - Usually has a built-in switch, but also performs DHCP functions and normally also has a built-in firewall.
Most enterprise-class switches have the functionality of a home router, but other features as well.
<font color=orange>Quarter</font color=orange> <font color=blue>Pounder</font color=blue> <font color=orange>Inside</font color=orange>
Don't step in the sarcasm!
Routers receive and transmit data based on IP addressing. You can set up internal LANs with the use of a router and some subnetting.
Hubs receive data from NICs, and sends it out of all open ports. It is essentially a multi-port repeater.
A switch is effectively a hub with the ability to control the traffic passing through it. It regulates traffic by the use of MAC addresses (unique IDs on NICs). It sends data only to the host which posseses the MAC address specified by the sender.
A hub, being by far the cheapest option also increases the amount of unnecessary traffic on the LAN. The use of switches and routers allows for a more effecient network.
<b><font color=blue>~ Whew! Finished...Now all I need is a Cyrix badge ~ </font color=blue> :wink: </b>