AWS Security Group

A security group acts as a virtual firewall for your EC2 instances to control incoming and outgoing traffic. Inbound rules control the incoming traffic to your instance, and outbound rules control the outgoing traffic from your instance. When you launch an instance, you can specify one or more security groups. 

If you don't specify a security group, Amazon EC2 uses the default security group. You can add rules to each security group that allow traffic to or from its associated instances. You can modify the rules for a security group at any time. 

New and modified rules are automatically applied to all instances that are associated with the security group. When Amazon EC2 decides whether to allow traffic to reach an instance, it evaluates all of the rules from all of the security groups that are associated with the instance.

When you launch an instance in a VPC, you must specify a security group that's created for that VPC. After you launch an instance, you can change its security groups. Security groups are associated with network interfaces.

The rules of a security group control the inbound traffic that's allowed to reach the instances that are associated with the security group. The rules also control the outbound traffic that's allowed to leave them.

The following are the characteristics of security group rules:

By default, security groups allow all outbound traffic.

Security group rules are always permissive; you can't create rules that deny access.

Security groups are stateful — if you send a request from your instance, the response traffic for that request is allowed to flow in regardless of inbound security group rules. For VPC security groups, this also means that responses to allowed inbound traffic are allowed to flow out, regardless of outbound rules.

You can add and remove rules at any time. Your changes are automatically applied to the instances that are associated with the security group

When you associate multiple security groups with an instance, the rules from each security group are effectively aggregated to create one set of rules. Amazon EC2 uses this set of rules to determine whether to allow access.

Open your AWS console and type VPC on find service and open that

Click on Security Groups

Click on Create Security Group to Create Security Group 

Mention these details in require field and click on Create Security Group