Security Group

The connection between Amazon EC2 Security Groups (SG) and Amazon EC2 Virtual Private Clouds (VPCs) is an essential part of security in AWS. SGs provide the basic firewall protection for your VPC, while VPCs provide the virtual networking layer on which all other components of your cloud infrastructure are built. By combining these two components, you can create a secure environment within which to run applications and manage resources. SG rules specify what traffic is allowed into and out of an instance located within a VPC, allowing you to limit access to only those services that are necessary for your application. By default, SG rules allow all traffic from any source IP address to any destination port on an instance in the same VPC as the SG itself; however, this can be changed by modifying the rules or creating new ones. Additionally, SG rules can be used to filter traffic from outside a particular region or even from specific IP addresses or networks. VPCs provide isolated areas of your cloud environment with their own private subnets and routing tables that define how traffic flows between them and other parts of your network architecture. This isolation ensures that different parts of your system remain separate from each other while still allowing communication via dedicated connections such as Direct Connect or VPN tunnels. Together with proper configuration and use of security groups, this level of isolation helps protect against malicious activity originating outside your network perimeter—allowing you to safely run applications without fear that they will be compromised by external threats such as malware or malicious actors attempting unauthorized access.