Iam Policies

In IAM, policies and permissions are closely related but distinct concepts.

Policies are documents that define the permissions for an entity, such as a user or role. They specify what actions are allowed or denied on specific resources. Think of policies as a set of rules that govern access to resources.

Permissions, on the other hand, determine what actions an entity can perform on a resource. Permissions are granted or denied based on the policies attached to the entity or resource.

To illustrate the difference:

A policy might state that a user can read and write to a specific S3 bucket.

The permission would be the actual ability to read and write to that bucket, as defined by the policy.

Key aspects of policies and permissions:

Effect: Policies specify whether to allow or deny access (Allow/Deny).

Action: Policies define the specific actions that are allowed or denied (e.g., s3:ListBucket).

Resource: Policies specify the resources affected by the policy (e.g., an S3 bucket).

Principal: Policies identify the entity (user, role, or group) to which the policy applies.

Types of policies:

Identity-based policies: Grant permissions to an entity (user, group, or role).

Resource-based policies: Control access to a specific resource, such as an S3 bucket.

Permission boundaries: Limit the maximum permissions an entity can have.

By understanding policies and permissions, you can effectively manage access control and ensure that your resources are secure.