Until recently, home networks were primarily the realm of technophiles - most families either didn't need or couldn't afford more than one computer. But now, one computer is no longer enough to go around for many families. In a household with multiple computers, a home network often becomes a necessity rather than a technical toy.

If you have two or more computers in your home, a network can let them share: Files and documents, an Internet connection, printers, scanners and other devices.

The different network types use different hardware, but they all have the same essential components:
- More than one computer
- Hardware (such as a router) and software (either built in to the operating system or as a separate application) to coordinate the exchange of information
- A path for the information to follow from one computer to another

The two most popular home network types are wireless and Ethernet networks. In both of these types, the router does most of the work by directing the traffic between the connected devices. By connecting a router to your dial-up, DSL or cable modem, you can also allow multiple computers to share one connection to the Internet. Many new routers combine wireless and Ethernet technology and include a hardware firewall.

If you're going to connect your network to the Internet, you'll need a firewall. A firewall is simply a program or hardware device that protects your network from malicious users and offensive Web sites. Many software firewalls block all incoming information by default and prompt you for permission to allow the information to pass. In this way, a software firewall can learn which types of information you want to allow into your network.