In networking, the size of the facility matters, but not as much as you might think. A 3-computer network attached to the Internet has exactly the same fundamental pieces and parts as a 1,000-computer enterprise network. The differences become apparent in the features you need to manage and secure the bigger network. Generally, network components are designed for one of four types of use: small office and home, small and medium enterprise, large enterprise, and carrier. The differences among these classes of products are in what we call the "-ities"--availability, capacity, manageability, reliability, scalability, and security.

The highest grade of products provide reliability of 99.9999 percent uptime per year. They support expansion, monitor their own operation and report their problems, and possess many flexible security functions. The least expensive products carry one-year warranties and function as "black boxes"--you plug them in and they work. But black boxes offer little flexibility or scalability.

People don't want networks, specifically; they want the benefits that networks provide. So, although this buying guide will clearly differentiate the pieces and parts of networking, it will focus more on the benefits of the technology rather than the technology itself. We'll also provide references for helpful technology discussions on the PC Magazine and ExtremeTech Web sites. We'll introduce the basic pieces and parts of a network, describe how they scale in functions and features, offer a guide to costs, and discuss the reality behind some networking myths.