This article aims to explore the distinction between IAM roles and IAM users in the context of Amazon Web Services (AWS).

IAM users are permanent entities with long-term credentials that enable direct interaction with AWS services. They can have passwords and access keys and may be associated with AWS resources or belong to a group.

In contrast, IAM roles do not possess credentials and are designed to be assumed by authorized entities. These roles are primarily used for federated logins and cannot make direct requests to AWS services.

AWS supports three types of roles: AWS service roles, Cross-Account Access, and Identity Provider Access. Service roles are specific to AWS services, Cross-Account Access grants permissions to users from other AWS accounts, and Identity Provider Access allows permissions for users authenticated by a trusted external system.

Both IAM users and roles employ policies for authorization, but IAM role credentials are temporary, providing more granular control and flexibility. Roles can be assumed by AWS resources, catering specifically to AWS services rather than physical individuals.

IAM Role vs IAM User

IAM roles and IAM users in AWS have distinct characteristics.

IAM roles do not possess any credentials and are intended to be assumed by authorized entities, such as federated logins.

On the other hand, IAM users have permanent long-term credentials and can directly interact with AWS services.

IAM roles are essentially a capability given to an IAM user, allowing for more granular control and flexibility in access management.

IAM roles do not have permanent access keys and cannot make direct requests to AWS services.

In contrast, IAM users can have passwords, access keys, and can belong to groups.

IAM users can also be associated with AWS resources.

Overall, IAM roles and IAM users serve different purposes and have different capabilities within the AWS environment.

Role Types

AWS supports three types of roles: AWS service roles, Cross-Account Access, and Identity Provider Access.

AWS service roles are specific to AWS services and are used to grant permissions to these services.

Cross-Account Access allows users from other AWS accounts to access resources in another account. This type of role is useful for organizations that need to delegate access to their resources.

Identity Provider Access grants permissions to users authenticated by a trusted external system. This allows users to sign in using their existing credentials from a trusted identity provider.

These different role types provide flexibility in managing access to AWS resources and cater to various scenarios and requirements within an AWS environment.

Authorization and Policies

Authorization and policies are essential components in managing access to resources within a cloud computing environment.

In AWS, both IAM users and roles utilize policies for authorization. While IAM users have permanent credentials, IAM roles have temporary credentials.

IAM users and roles require specific actions to be allowed with a policy, but they have different authentication methods. IAM users can directly interact with AWS services, whereas IAM roles cannot make direct requests.

IAM roles act as a capability given to IAM users, allowing for more granular control and flexibility in access management.

Policy documents, which are JSON documents, handle permissions and can be attached to IAM users, groups, and roles.

IAM roles can be assumed by resources like EC2 instances or Lambda functions, providing temporary access to AWS resources.