AWS Security Groups
- Security Groups are the fundamental of network security in AWS.
- They allow us to manage and control, how traffic should be allowed into or out of our AWS services created.
- It states how to use security groups to allow, inbound and outbound ports. It simply acts as an “firewall” on AWS services

Security Group Features
Security group regulates:
- Access to Ports
- Authorized IP ranges – IPv4 and IPv6
- Control of inbound network (from other to the instance)
- Control of outbound network (from the instance to other)
Additional features to know
- One security group can be attached to multiple instances
- It’s good to maintain one separate security group for SSH access
- If your application is not accessible (time out), then it’s a security group issue.
- If your application gives a “connection refused“ error, then it’s an application error or it’s not launched.
- All inbound traffic is blocked by default.
- All outbound traffic is authorized by default.