AWS Certified Cloud Practitioner

Explanation

When creating security groups in AWS, the customer is responsible for:

A. Giving a name and description for the security group - This is a customer responsibility as they need to provide meaningful names and descriptions for their security groups to identify their purpose.

B. Defining the rules as per the customer requirements - Customers must define the inbound and outbound rules based on their specific application and security requirements.

C. Ensure the rules are applied immediately - This is managed by AWS infrastructure automatically, not a customer responsibility.

D. Ensure the security groups are linked to the Elastic Network interface - While customers do associate security groups with resources, the actual linking to ENIs is handled by AWS infrastructure.

Security groups act as virtual firewalls for EC2 instances to control inbound and outbound traffic. Customers are responsible for configuring the security group rules according to their security needs, while AWS handles the underlying infrastructure and rule enforcement.