What is the main purpose of a gateway in a network?

A gateway serves as a critical node in a network, primarily responsible for managing communications between different networks. It acts as a "gate" that enables data to flow between networks that operate using different protocols or architectures. This is essential for ensuring that devices located in separate networks can exchange information, which is a foundational aspect of networking, especially in connecting local networks to the internet or connecting two different types of networks (such as a local area network (LAN) and a wide area network (WAN)).

In the context of the other options, providing local DNS services refers to translating domain names into IP addresses, which is typically handled by DNS servers rather than gateways. Assigning IP addresses is the role of a DHCP server, which is responsible for dynamically assigning IP addresses to devices within a network. Monitoring network traffic is usually conducted by specialized devices and software dedicated to network analysis, such as network monitoring tools or intrusion detection systems, rather than gateways themselves. These functions are distinct from the primary role of a gateway, which focuses on facilitating communication between different networks.