A software-defined LAN that groups users by logical addresses into a virtual, rather than physical, LAN through a switch or router. Users within a VLAN traditionally are grouped by physical ports, Transmission Control Protocol (TCP) port address, medium access control (MAC) address, or Internet Protocol (IP) address. A LAN switch or router can support many VLANs, which operate as subnets. See also IP, LIS, MAC, physical, port, subnet, TCP, and virtual.