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LANs, WANs, and MANs
Most early PC networks focused on interconnecting computers within a single physical location, such as an office or a college campus. Networks which span such a limited physical space are called local area networks, or LANs. Even then, however, there were networks that connected computers to other, far away computers, such as on another college campus, another company, or a corporate office in another city. Such networks are called wide-area networks, or WANs. There are also networks that, while they cover a larger area than a LAN, nonetheless cover a fairly limited geographic entity such as a single city. Such networks are usually designated as metropolitan area networks (MANs).