Guide to Federated Access & Identity Federation in AWS

Federated Access and Identity Federation are vital components in AWS, especially for AWS IAM (Identity and Access Management).

What is it?
Federated Access in AWS IAM pertains to the process of linking a user's identity from an external identity provider to an IAM role. It allows users to authenticate using their own organizational identities to access AWS resources. Identity Federation, on the other hand, is a broader concept that pertains to the combination of different identity management systems.

Why is it important?
It negates the need for multiple credentials as users can use their existing identities. This simplifies access management, enhances security, and increases efficiency.

How does it work?
It generally works by the Identity provider (IdP) sending an authentication request to AWS, which AWS confirms. On successful confirmation, AWS generates an access token (typically STS tokens) which is used by the federated user to access AWS resources. These tokens are temporary and expire after a short duration.

Exam Tips: Answering Questions on Federated Access and Identity Federation
Understanding the underlying mechanism, key terms, and principles is particularly important for the exam. Remember, federated users are not permanent AWS IAM users and AWS never stores their credentials. And focus on the part where these tokens have a default and maximum duration.
Note: Security Token Service (STS), External Identity Providers (IdP), SAML 2.0 are some key terms associated with Federated Access and Identity Federation.

For answering exam questions, understand that any question pertaining to large organizations, providing temporary access or the use of organizational identities to access AWS often points towards Federated Access and Identity Federation.

Also, understanding federated login workflow and STS service will help you in answering scenario-based questions.