# Security Groups
#aws #cloud #networking
An AWS stateful firewall service that controls the traffic that is allowed to reach and leave the resources that it is associated with in an instance level.
When you create a VPC, it comes with a default security group. You can create additional security groups for each VPC. You can associate a security group only with resources in the VPC for which it is created.
For each security group, you add rules that control the traffic based on protocols and port numbers. There are separate sets of rules for inbound traffic and outbound traffic.
Security group can be applied to aws resources within a VPC such as: EC2 RDS ELB
