Stands for "Internet Connection Sharing." ICS allows multiple computers to connect to the Internet using the same Internet connection and IP address. For example, several computers in a household can connect to same cable or DSL modem using a router. As long as the router is connected to the modem, every computer connected to the router is also connected to the Internet. Network address translation (NAT) allows the computers to share the same IP address.
ICS can also be done using software. Windows 98 and later, as well as Mac OS X, support Internet connection sharing. This allows one system's network settings to be modified, turning the computer into a gateway. Other computers on the same network can then use that computer's Internet connection. Windows users can also use programs such as WinGate and WinProxy to achieve the same result. While it is possible to share an Internet connection using software, using hardware (such as a router) for ICS is the easiest and most hassle-free solution.