What is the primary purpose of a router in a network?

The primary purpose of a router in a network is to connect different networks and route packets between them. Routers are designed to analyze the destination IP addresses of data packets and determine the most efficient path to forward those packets to their intended destination across multiple networks. This function is crucial in facilitating communication between devices on different local area networks (LANs) and wide area networks (WANs).

Routers make forwarding decisions based on the information they maintain in their routing tables, which include details about network topology and paths to different networks. By connecting various segments of a network, routers enable seamless data exchange, making them essential for internet connectivity and for interconnecting different subnets within an organization.

The other options represent important network functionalities but do not encapsulate the primary role of a router. While filtering incoming traffic based on IP addresses is a feature of some advanced routers and firewalls, and providing local network access to devices typically refers to switches or access points, encryption of data is not a basic router function – rather, it can be handled at higher layers of the network stack, often by other devices or software solutions.