AWS Identity and Access Management (IAM)

AWS IAM: Users, Policies, Groups, and Roles

AWS Identity and Access Management (IAM) is an essential service for managing access and authorization in the cloud. With security being a top priority, not all users are granted full access. IAM allows fine-grained control over what users can do within an AWS environment.

Users

IAM users are individuals who need to access AWS resources. They are assigned login credentials and are authenticated to enter the cloud environment. Typically, these are real people (e.g., employees or contractors) who need to interact with cloud services.

Policies

Policies define the permissions a user has within the AWS ecosystem. These determine what actions users can perform, such as creating or deleting S3 buckets. AWS provides a set of default policies, but you can also create custom policies by combining permissions from multiple policies to suit specific needs.

Groups

In larger organizations, many individuals work in similar roles. Rather than assigning the same permissions repeatedly to each user, groups allow you to bundle a set of policies. For example, frontend developers, backend developers, QA engineers, and managers may have different permissions. By grouping users and assigning policies to the group, you simplify management and ensure consistency.

Note: Users can still have individual policies assigned in addition to group-level permissions if needed.

Roles

While users are for human access, roles are primarily for application-based access. Roles provide temporary credentials that applications can use to perform tasks like fetching information from AWS services. This is particularly useful for automation or when an application needs to access AWS resources securely. If there’s a security breach, you can easily revoke a role to mitigate risks.