While there are many different classifications of networks, some key components include nodes, hosts, media, data, and network devices. Each serves a specific purpose: a node is any device on the network that actively transmits and receives information; a host is a node that marks the beginning or end of communication; media refers to the physical pathway connecting the nodes; data is the information carried by the media, formatted using standardized rules called protocols; and a network device is a node that functions as part of the network’s structure rather than as a host of resources. There are also physical networks, made up of interface cords, hardware, cables, and other visible components, and logical networks, which represent the information carried and the path it follows, something the computers can “see” but we cannot physically observe.