A computer network is a digital telecommunications network. It involves computing devices that exchange data with each other using connections between nodes. Wireless media such as Wi-Fi or cable media like optic cables or wires are used to establish these data links. Interpersonal communications are facilitated by computer networks, which allow users to communicate easily and efficiently through different means. Shared use of application and storage servers, use of email and instant messaging, access to the World Wide Web, etc. are some of the applications and services supported by computer networks. The wired technologies used for networking include coaxial cable, optical fiber and twisted pair cabling. The wireless technologies include terrestrial microwave communication, radio and spread spectrum technologies, communication satellites and free-space optical communication. This book studies, analyzes and upholds the pillars of computer networks and communication and its utmost significance in modern times. It is a valuable compilation of topics, ranging from the basic to the most complex advancements in this field of study. It will help new researchers by foregrounding their knowledge in this branch.