Subnets

A subnet, which is short for subnetwork, is a logical division of a network into a smaller unit. To create subnets, the network administrator configures each node with a network and a node address (called an IP address) and a subnet mask (which is used to identify the subnet to which the node belongs) in order to divide the network into subnetworks. Routers and switches act as the borders of each subnet and manage traffic within and between subnets on a network. The subnet can be on a seperate physical segment, or it can share segments with other logical subnets.

Two main benefits of creating subnets are to improve network performance and to provide a more secure network environment. For performance enhancement, an administrator would most likely divide the network into group of devices that frequently interact with each other, and for security enhancement, the administrator might divide the network based on servers that have restricted applications or sensitive data.