A LAN segment is an installation-related subsection of a local area network (LAN) in which traffic only takes place between the stations that are located within the segment. Each individual LAN segment operates with the same access procedures as the entire local network and forms a self-contained collision domain.
Segmentation offers the advantage of load balancing because, when properly segmented, much of the traffic is confined to the LAN segment and does not load the entire local network. For example, in a company, one LAN segment may be designed for administration, another for production, and a third or fourth for research and engineering. In this constellation, the individual subnets are not or only slightly loaded by the traffic of the other subnets.
The segment-oriented data traffic in the individual LAN segments is kept away from the rest of the network by internetworking components such as bridges or routers. If the network coupling is done by bridges, then the path selection function is based on bridging, in case of routers by means of routing. The coupling elements can increase the total throughput between the LAN segments to a multiple of the respective local transmission capacity.