AWS Identity and Access Management (IAM)
AWS Identity and Access Management (IAM) provides fine-grained access control across all of AWS. With IAM, you can specify who can access which services and resources, and under which conditions. With IAM policies, you manage permissions to your workforce and systems to ensure least-privilege permissions.
IAM is an AWS service that is offered at no additional charge. To get started using IAM or if you have already registered with AWS, go to the IAM console.
Use cases
With IAM, you can manage AWS permissions for workforce users and workloads. For workforce users, we recommend that you use AWS Single Sign-On (AWS SSO) to manage access to AWS accounts and permissions within those accounts. AWS SSO makes it easier to provision and manage IAM roles and policies across your AWS organization. For workload permissions, use IAM roles and policies, and grant only the required access for your workloads.
Apply fine-grained access control
Grant access to specific AWS service APIs and resources by using IAM policies. You also can define specific conditions in which access is granted, such as granting access to identities from a specific AWS organization or access through a specific AWS service.
Establish permissions guardrails and data perimeters across your AWS organization
With AWS Organizations, you can use service control policies (SCPs) to establish permissions guardrails that all IAM users and roles in an organization’s accounts adhere to. You also can establish a data perimeter to help ensure that only your trusted identities are accessing trusted resources from expected networks. Whether you’re just getting started with SCPs or have existing SCPs, you can use IAM access advisor to help you restrict permissions confidently.
Achieve least-privilege permissions with IAM Access Analyzer
Achieving least privilege is a continuous cycle to grant the right fine-grained permissions as your requirements evolve. IAM Access Analyzer helps you streamline permissions management as you set, verify, and refine permissions.
Automatically scale fine-grained permissions with ABAC
Attribute-based access control (ABAC) is an authorization strategy for creating fine-grained permissions based on user attributes, such as department, job role, and team name. With ABAC, you can reduce the number of distinct permissions you need for creating fine-grained controls in your AWS account.
How it works
With IAM, you define who can access what by specifying fine-grained permissions. IAM then enforces those permissions for every request. Access is denied by default and access is granted only when permissions specify an "Allow."

Learn more about IAM