Final answer:
A ring network lacks a hub, which is used in star topologies. In a ring network, each node connects to exactly two other nodes, and there's no need for a central hub.
Step-by-step explanation:
A ring network is a type of computer network configuration where each node (computer or network device) is connected to two other nodes, forming a single continuous pathway for signals through each node - a ring. In a ring network, data travels in one direction, and each device has exactly two neighbors for communication purposes. The question asks what a ring network lacks, and the answer is a hub. Hubs are used in star topologies where each node is connected to a central hub that manages and controls the network traffic.
In contrast to ring networks, other common network typologies include the bus, star, and mesh networks. A peer-to-peer (P2P) network is where two or more PCs are connected and share resources without going through a separate server computer. A node is simply a connection point in a network. A network interface card (NIC) is a hardware element that enables a PC or other device to connect to a network.