 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 media, from a real network. When you slap a floppy disk 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, wireless networks, which are devoid of 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, 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 as a group of buildings under the control of one entity, such as a college or a single company). An argument could be made that the terms MAN and CAN can be interchanged, and in some cases, this is true. (Conversely, there are plenty of people out there who would argue that a CAN exists only in certain specific circumstances, and that calling a CAN by any other name is madness.) The difference is usually that in a campus environment, there will probably be conduits to allow direct physical connections between buildings, wh