Definition
Segmentation refers to the practice of dividing a computer network or system into smaller, isolated sections or segments. This division is typically achieved using firewalls, virtual local area networks (VLANs), or access control lists to control traffic flow between segments. Segmentation is crucial for enhancing security by limiting the lateral movement of threats and reducing the attack surface. For instance, a company might segment its guest Wi-Fi network from its internal corporate network to prevent unauthorized access to sensitive data. Unlike network subnetting, which primarily addresses IP address allocation and routing efficiency, segmentation focuses on security boundaries and traffic policy enforcement. This concept is fundamental to domains like network security and cloud security, appearing in certifications such as CompTIA Security+ and AWS Certified Solutions Architect.