What is the intent behind using a permissions boundary in IAM policies?

The intent behind using a permissions boundary in IAM policies is to restrict permissions based on defined limits. A permissions boundary is a powerful feature in identity and access management (IAM) that sets the maximum permissions a user or role can have, even if other policies grant broader permissions. This helps organizations implement the principle of least privilege, ensuring that users cannot escalate their permissions beyond what is explicitly allowed by the boundaries set in place.

By establishing these boundaries, organizations can tightly control access and mitigate risks associated with over-provisioning permissions. For instance, if a development team is granted permissions to manage resources, a permissions boundary can be used to ensure that their access is limited to only those resources necessary for their tasks, preventing unauthorized access to critical or sensitive data.

In contrast, other options either misinterpret the function of a permissions boundary or do not align with its purpose. Delegating permissions to external users doesn't directly relate to how permissions boundaries function, as boundaries are about restricting internal permissions. Creating unlimited access contradicts the very essence of establishing boundaries, which is to limit that access, and removing complexities in access control does not accurately describe what a permissions boundary does, as it often introduces additional layers to think about when managing permissions.