What is the main function of a VLAN?

The main function of a VLAN, or Virtual Local Area Network, is to segment traffic across networks. VLANs allow network administrators to create logically separated networks within a single physical network structure. This segmentation enhances security and performance by isolating traffic. For instance, different departments within an organization can have their own VLANs, which reduces broadcast traffic and minimizes the risk of sensitive information being accessed by unauthorized users.

This traffic segmentation can lead to improved performance because devices within the same VLAN communicate directly with reduced latency, as they don't have to contend with unnecessary traffic from other VLANs. VLANs also facilitate better management of network resources and simplify the implementation of policies.

Other options, while they may improve aspects of network management, do not align with the primary purpose of a VLAN. For example, backing up data efficiently pertains to data storage solutions rather than network segmentation, and connecting multiple servers relates more to network architecture than to the specific purpose of VLANs. Therefore, focusing on the isolation and management of network traffic underscores why the correct choice is about segmenting traffic across networks.