Dynamic segmentation is a network defense technique that divides systems, devices, or applications into small trust zones and changes those boundaries based on policy, identity, or context. Instead of treating an entire subnet as trusted, access is granted only between approved endpoints and only for the traffic that is needed.
This matters because it limits lateral movement. If an attacker compromises one workstation, server, or controller, segmentation can prevent them from reaching other assets and reduce the blast radius of the intrusion. In real environments, it is used with zero trust, least privilege, and virtual patching to protect fragile or hard-to-update systems. Defenders apply it in OT, data centers, and cloud networks to isolate critical assets, contain malware, and keep exposed services from becoming a path to deeper compromise.