AWS Security Group is a virtual firewall that controls inbound and outbound traffic for Amazon Elastic Compute Cloud (EC2) instances and other resources in Amazon Web Services (AWS). It acts as a virtual firewall that regulates traffic based on rules that you define.
Each AWS Security Group is associated with one or more instances, and you can specify the inbound and outbound traffic rules for that group. You can use security groups to allow or deny traffic from specific IP addresses, protocols, or ports. You can also create rules that allow traffic from other security groups, enabling you to control access to different resources within your VPC.