What Does Subnetwork Mean?

A subnetwork (subnet) is a separate and identifiable portion of an organization’s network, typically a local area network (LAN) comprised of all the machines on one floor, building or geographical location. Having several subnets allows an organization to be connected to the Internet with a shared network address, which means that all the machines on a given subnet have the same prefix to their IP addresses.


The practice of dividing a network into subnets is called subnetting.

Techopedia Explains Subnetwork

The subnetting process involves separating the network and the subnet portion of the IP address from the host identifier, which consists of the network prefix, the subnet number (also called a subnet mask) and the host number. The network prefix identifies the entire network, the subnet number identifies a portion of the entire subnetwork and the host number identifies the host computer.

Data traffic between subnets is controlled by gateway computers called routers, which act as physical borders between subnets.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.