What is a VLAN and why is it used?

A Virtual Local Area Network (VLAN) is a technology used to create logically separated networks within a single physical network infrastructure. This segmentation allows network administrators to isolate traffic for improved performance and security. By dividing a large network into smaller, manageable segments, VLANs help reduce broadcast traffic, which can enhance overall network efficiency.

VLANs accomplish this by grouping devices that may not be physically connected to the same switch or hub but are logically part of the same network. This classification enables different departments, teams, or functional areas within an organization to have their own network segment, thereby limiting the broadcast domain and enhancing security by restricting access to sensitive information.

In addition, VLANs facilitate better resource allocation and management, enabling policies to be applied consistently across devices regardless of their physical location. This flexibility supports various networking scenarios, such as supporting VoIP, managing user mobility, and maintaining security protocols.

While other options mention various aspects of networking, they do not accurately represent the concept of VLANs or their primary purpose in network design and management.