A subnet (subnetwork) is a smaller network created within a Virtual Private Cloud (VPC). It helps organize and isolate AWS resources based on their purpose and security requirements.
With subnets, you can place resources like Amazon EC2 instances in different network segments. A public subnet allows internet access, while a private subnet is used for internal resources such as databases and application servers.
In simple words, a subnet divides a VPC into smaller networks, making it easier to manage, secure, and organize cloud resources.