A network node is any device that connects to a computer network and can send, receive, or forward data. This includes devices like computers, routers, switches, and servers. Each node has a unique identifier, such as an IP address, which allows it to communicate with other nodes in the network. In a network, nodes work together to facilitate data transfer and ensure efficient communication. For example, a router directs data packets between different nodes, while a server provides resources or services to other nodes. Overall, network nodes are essential for the functionality and performance of any network.