A router is generally used to allow multiple devices to share one connection.
e.g. in our house we have a number of PCs, a PS3, and iPod touches, which all share one broadband connection via a wireless router (some wired, some wireless).
It's generally of little use if you only have one device, although some do have security systems which may be of use, or you wish to set up a VPN etc.
A router is a network device for connecting two or more networks. In your case it is connecting a WAN (the Internet) to a LAN (Your private network to which you PC is attached via an Ethernet cable.).
Additionally domestic routers, such as you almost certainly have, have other network devices and software hidden under the covers to make things easier for end users. For example: ADSL Modem, Ethernet Switch, Wireless Access Point, Firewall, DHCP Server.
A lot of this stuff is like Mrs Rumpole's Vim. "You'd soon notice if I didn't buy Vim Rumpole!" It makes life easier for you even though you may not see what is is doing - particularly the Firewall.
A router is generally used to allow multiple devices to share one connection.
e.g. in our house we have a number of PCs, a PS3, and iPod touches, which all share one broadband connection via a wireless router (some wired, some wireless).
It's generally of little use if you only have one device, although some do have security systems which may be of use, or you wish to set up a VPN etc.
