A virtual local area network is a logical subnetwork that groups a collection of devices from different physical LANs. Large corporate computer networks often set up VLANs to repartition a network for better traffic management. Several types of physical networks support virtual LANs, including Ethernet and Wi-Fi.

When configured correctly, virtual LANs can improve the performance of busy networks. VLANs can group client devices that communicate frequently with each other. Traffic between devices that are spread across two or more physical networks is typically handled by a network's core routers. With a VLAN, that traffic is handled more efficiently by network switches.

VLANs also bring security benefits to larger networks by providing more control over which devices have local access to each other. Guest Wi-Fi networks are often implemented using wireless access points that support VLANs.

Network administrators often refer to static VLANs as port-based VLANs. In a static VLAN, an administrator assigns individual ports on the network switch to a virtual network. Whatever device is connected to that port, it becomes a member of that particular virtual network.