AWS IAM - Identity and Access Management

Amazon Resource Name (ARN)

What is an ARN?

Amazon Resource Name (ARN) is a unique identifier assigned to AWS resources. It follows a standardized format:

arn:partition:service:region:account-id:resource
  • partition → Usually aws, but can be aws-us-gov for government clouds.
  • service → The AWS service (e.g., s3, ec2, lambda).
  • region → AWS region where the resource is hosted.
  • account-id → The AWS account number.
  • resource → The specific resource identifier.

Examples of ARNs

AWS Service ARN Example
IAM User arn:aws:iam::123456789012:user/JohnDoe
S3 Bucket arn:aws:s3:::my-bucket
S3 Object arn:aws:s3:::my-bucket/myfile.txt
EC2 Instance arn:aws:ec2:us-east-1:123456789012:instance/i-abcdef123456
Lambda Function arn:aws:lambda:us-west-2:123456789012:function:MyFunction
RDS Database arn:aws:rds:us-west-2:123456789012:db:mydatabase