AWS (Amazon Web Services) Certification Practice Exam

What do Access Control Lists (ACLs) in S3 typically control?

1. Access for users within the same AWS account

2. Access for users outside of the AWS account

3. Cost management and billing

4. Standard retrieval performance

The correct answer is: Access for users outside of the AWS account

Access Control Lists (ACLs) in Amazon S3 are used to manage access permissions for the resources stored in S3 buckets. ACLs allow you to define who can access your bucket and its objects and what actions they can perform—such as read or write access. While ACLs can indeed control access for users outside of your AWS account, they also provide the capability to manage access for users within the same account. The focus on managing access for external users is significant; ACLs let you specify permissions for AWS accounts that are not directly related to your account, essentially enabling you to share your resources with outside parties. Cost management and billing do not fall under the control of ACLs; instead, they relate to AWS account management and service usage monitoring. Similarly, standard retrieval performance relates to how S3 handles operations regarding data access and retrieval speed, which is unrelated to permissions or access controls provided by ACLs. In essence, ACLs are solely concerned with permissions rather than billing or performance, and they serve a key role in securing your data, especially when it comes to interactions with entities outside of your AWS account.