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security groups aws

From AWS Documentation:
A security group acts as a virtual firewall, controlling the traffic 
that is allowed to reach and leave the resources that it is associated with. 
For example, after you associate a security group with an EC2 instance, 
it controls the inbound and outbound traffic for the instance.

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.

how to create security group using aws cli

aws ec2 create-security-group --group-name MySecurityGroup --description "My security group"

how to create security group using aws cli

{
    "GroupId": "sg-903004f8"
}