A security group acts as a firewall to control access to a cloud machine.
A fabric administrator specifies at least one security group when creating an Amazon EC2 reservation. Each available region requires at least one specified security group. The reservation form displays the security groups that are available to an Amazon Web Services account region. Every region includes at least the default security group.
Administrators can use the Amazon Web Services Management Console to create additional security groups, configure ports for Microsoft Remote Desktop Protocol or SSH, and set up a virtual private network for an Amazon VPN.
For information about creating and using security groups in Amazon Web Services, see Amazon documentation.