If you're looking to connect multiple network devices together throughout the home, you'll usually find that a switch gives you a faster connection between the devices than using a router on it's own as most switches run 10 times faster than the ports usually found on the back of routers. Switches are also a great way of expanding the number of static devices (i.e wired) that can be connected by increasing the number of ports available. Most standard home routers feature 4 ports which can be quickly used up in a house filled with gadgets so a switch is ideal for giving you more connections or to save the effort of running many cables to your (usually inconveniently located) router, cable everything to a more centrally located switch, then just run a single cable to your router to provide internet access to all the devices on the switch.
The speed of a switch and number of ports available will vary depending on the model and of course how much you are willing to spend. Speeds of low end switches run at 100mbps but the faster gigabit switches can run at ten times this speed, which is ideal for the rapid transfer of data between devices across the home network. Another thing to consider when selecting a switch for home use is to check that the switch is fanless, as some switches are fitted with a small high speed fan that can quite often be heard over the TV.
