Network segmentation involves separating a network into distinct sections to improve its performance and security. Each segment can be managed independently while allowing for better control over traffic, resources, and policies. By grouping users or devices that share the same function, organizations can enhance their security measures, as breaches in one segment will not necessarily compromise the whole network. Additionally, segmentation can help with troubleshooting and optimize network management, making it easier to identify and resolve issues without impacting the entire network.