Computer and Communication Networks refer to the infrastructure that allows computers and other devices to connect and communicate with each other. These networks enable the transfer of data and resources across various systems, both locally and globally. They consist of various hardware (routers, switches, cables) and software protocols that ensure reliable communication. Networks can be classified into types based on their geographical range, such as Local Area Networks (LAN), Wide Area Networks (WAN), and Metropolitan Area Networks (MAN). Communication technologies like the internet, Wi-Fi, and mobile networks rely on these networks for data transmission.