The primary function of a network switch in a data center is to manage data traffic between devices within the network efficiently. Acting as a central point of connection, switches facilitate communication between servers, storage devices, and other networked equipment. They operate at the data link layer of the OSI model, directing data packets to their intended destinations using MAC addresses. This process reduces network congestion and improves overall performance. Modern switches also offer features like VLANs and network monitoring, enhancing security and management capabilities within data centers.