There are several ways to hook up individual computers into a network. One is to use hardware routers to link up the network segments. If you buy hardware bridges, those will also connect the computers with each other. In Windows XP, simply clicking the "Bridge Connections" icon joins parts of a network together, even if the parts use different media to link their segments.
Using a router or a hardware bridge requires buying more equipment to connect your computers. With a wireless router, each computer and network segment needs its own Internet Protocol (IP) address in order to direct data to the right computer. Both methods may require an IT professional or experienced amateur to connect everything properly. With Windows XP, building a bridging connection requires just a few clicks of your mouse in the right places.
To make a bridge, you must log in as an administrator on your network or your computer. Click the computer's "Control Panel," then "Network and Internet Connections" and "Network Connections." Select at least two connections from the list to form a bridge; you can only form one bridge on one computer, but each bridge accommodates multiple connections. If you create a bridge directly to your network's Internet connection, this will compromise security and leave your network vulnerable to intruders.
Network bridging is useful if your office or home is a mixed-network environment. If you have a couple of computers linked by an Ethernet cable and a couple more that link via a wireless router, that constitutes a mixed network. In a traditional network, you would have to put each of the different media on its own subnet, with a system called packet forwarding transmitting information from one subnet to another. With network bridging, the bridge automatically converts information into a suitable form when connecting subnets.
If you have an earlier edition of Windows than XP, you don't have the network bridging option. The network bridge only links Ethernet connections, Ethernet-compatible adapters and IEEE1394 adapters into a network, and IEEE1394 adapters will only support certain kinds of traffic. If an adapter has Internet Connection Sharing (ICS) or Internet Connection Firewall (ICF) enabled, you can't bridge to it. Your computer cannot even show it as a potential connection.