Network segmentation divides a network into multiple parts, known as segments. Each segment acts as an isolated fragment of the network. Network administrators can assign different monitoring policies to different segments and put access controls on the traffic between segments. If a corporate network is segmented wisely, most traffic stays between devices and applications within each segment, with much less traffic crossing segment boundaries. Hence, segmentation improves network monitoring, performance, and security. 

Network segmentation prevents unauthorized user access and malicious attacks on medical devices by containing attacker activity to disparate parts of the network. Generally speaking, more network segments lead to a more secure network. The challenge is to avoid over-segmentation which can hurt connectivity, or under-segmentation which can create security and operational risks, while maintaining segmentation integrity over time.