A subnet (subnetwork) is a segmented portion of an IP network created by dividing a larger network into smaller, manageable sections. Subnets improve routing efficiency, security, and organizational structure within cloud or enterprise networks. Each subnet is defined by a network address and a subnet mask.
Why it matters
Subnets allow administrators to isolate resources, control traffic flow, and enforce security boundaries. They are fundamental to cloud networking, enabling private networks, public endpoints, and multi-tier architectures.
Examples
Creating public and private subnets in a VPC or segmenting office networks by department. Lessons like What Is a Subnet? explain subnetting.