Explanation Virtual LANs (VLANs) are used to segment a physical LAN into multiple logical LANs. This allows multiple networks to share a single physical LAN while maintaining the logical separation between the networks. Each VLAN is assigned a unique identifier and each network device is configured with the identifier of the VLAN it belongs to. This allows traffic from different VLANs to be identified and routed accordingly. VLANs provide an additional layer of security by ensuring that devices on one VLAN cannot access the traffic of another VLAN.