Security Groups

Security groups are virtual firewalls applied at the resource level in cloud environments, controlling which traffic is allowed to reach individual instances, containers, or services based on rules that specify protocol, port range, and source or destination IP address. Unlike traditional network firewalls that sit at the perimeter, security groups travel with the resource and enforce rules wherever that resource is deployed within the cloud. Most cloud providers implement security groups as stateful, meaning if an inbound connection is allowed, the corresponding outbound response is automatically permitted without needing an explicit outbound rule.