stributed Data Interface (FDDI) networks, Asynchronous Transfer Mode (ATM) networks, Frame Relay networks, T1 networks, DS3 networks, bridged networks, routed networks, and point-to-point networks, to name a few. If you're old enough to remember the program Laplink, which allowed you to copy files from one computer to another over a special parallel port cable, you can consider that connection a network as well. It wasn't very scalable (only two com- puters) or very fast, but it was a means of sending data from one computer to another via a connection. Connection is an important concept. It's what distinguishes a sneaker net, in which information is physically transferred from one computer to another via removable me- dia, from a real network. When you slap a USB drive (does anyone still use floppy disks?) into a computer, there is no indication that the files came from another computer-there is no connection. A connection involves some sort of addressing or identification of the nodes on the network (even if it's just master/slave or primary/ secondary). The machines on a network are often connected physically via cables. However, wire- less networks, which are devoid of obvious physical connections, are connected through the use of radios. Each node on a wireless network has an address. Frames received on the wireless network have a specific source and destination, as with any network. Networks are often distinguished by their reach. LANs, WANs, MANs, and CANs are all examples of network types defined by their areas of coverage. LANs are, as their name implies, local to something-usually a single building or floor. WANs cover broader areas, and are usually used to connect LANs. WANs can span the globe, and there's nothing that says they couldn't go farther. MANs are common in areas where technology like Metropolitan Area Ethernet is possible; they typically connect LANs within a given geographical region such as a city or town. A CAN is similar to a MAN, but is limited to a campus (a campus is usually defined a