This book describes computer networks from the perspective of administrators, pointing out that the network is fundamentally a private network consisting of a single independent system that cannot be accessed away from its physical and logical domains. The network may be a public network, it can be all-access, or a private network that only a few individuals can access. The book introduces computer networks and data communication, which is a system composed of interconnected computers and computer peripherals (such as printers and multimedia devices). This interconnection between computers facilitates information distribution between them. Wired and wireless multimedia communications are deliberated in the book. Similarly, there are topics about the physical and logical features of a network.