When we talk about home networks, we generally mean a system composed of at least two devices connected to each other. Usually, these devices also connect to the Internet. Technically, if you have only one device connected to the Internet, it's part of a larger network. But you wouldn't have a network of your own.
Computers running on the Windows operating system are more at risk of security invasions than Mac computers. That's to be expected -- the Windows operating system dominates the computer market. That means the Windows platform is a big target for people who want to exploit computers -- they've got a much larger target and potential payoff.
Other devices that can comprise a home network include routers, firewalls, cable or DSL modems, printers, video game consoles, smartphones and voice over Internet protocol (VoIP) phones. Depending upon the protocols you use, you may have even more devices linked to your network. For example, Bluetooth gadgets can sync with each other when they come within range of the network.
From a security standpoint, the pieces of hardware that will help provide security are firewalls and routers. Firewalls come in two varieties: hardware and software. You can purchase a physical firewall device or run a firewall application. Many routers have firewall software built into them.
Firewalls act like filters. They help you monitor data traffic between your network and the Internet. If you detect unusual traffic, that's a potential sign that someone has compromised your home network's security. Most firewalls have several security settings to choose from. The most restrictive settings are generally the safest, but they also limit your options. Most firewalls will allow you to create a list of Web addresses that are off limits.
If you use a wireless router, you should make sure you set a password and enable encryption. Unprotected wireless networks are a bad idea. Most routers have either Wireless Encryption (WEP) or Wi-Fi Protected Access (WPA) encryption options. Some have both. WPA is more secure than WEP. Enabling encryption and choosing a strong router administrator password are two steps that will help keep your network secure.