(SUBNETwork) A logical division of a local area network, which is created to improve performance and provide security. To enhance performance, subnets limit the number of nodes that compete for available bandwidth. Instead of one network handling all the traffic, the network is divided into groups of clients and servers that interact with each other most of the time. For security, the subnet divisions can be based on servers that have restricted applications. Routers are bridges are used to traverse network segments. In an IP network, the subnet is identified by a subnet mask (see subnet mask).