Final answer:
The network medium establishes communication channels between nodes in a network and can be wired or wireless, influencing the network's performance.
Step-by-step explanation:
The part of the network that establishes a communications channel between the nodes of the network is known as the medium or network medium. This medium can take various forms, such as twisted-pair copper wires, fiber-optic cables, or wireless signals. The choice of communication medium affects the speed and reliability of data transmission within the network infrastructure.