Microsegmentation involves dividing a network into smaller, isolated segments to restrict lateral movement within the network. This is crucial within a Zero Trust architecture, which assumes that no entity (internal or external) is inherently trustworthy. By limiting access to only necessary network segments, microsegmentation reduces the impact of a potential breach by containing it within a limited area. CompTIA emphasizes microsegmentation as an effective strategy to minimize risk and improve security posture by isolating resources based on the principle of least privilege.