Understanding IAM on AWS

Imagine you own a big house with different rooms — your bedroom, the kitchen, a home office, and a garage. Not everyone should have access to every room, right?
You might:

• Give your family keys to the whole house.
• Allow the cleaning service to enter only the living room and kitchen.
• Let a delivery person drop off packages at the doorstep but not enter.

This is exactly how AWS IAM which stands for(Identity and Access Management) works in the cloud! IAM helps control who can access what in your AWS account. Let’s break it down in a simple way.

AWS IAM is a security tool that manages users, groups, roles, and permissions to ensure that only the right people (or systems) have access to specific AWS resources.

For example, in a company:

• A developer should be able to start and stop servers (EC2 instances) but not see the company’s billing details.
• A database admin should be able to manage databases (RDS) but not delete files in storage (S3 buckets).
• A server (EC2 instance) may need to read data from storage (S3) but not make security changes.

This is known as the Principle of Least Privilege (PoLP) — giving users and services only the permissions they need, nothing more.

IAM Key Concepts
IAM Users – Who Gets In?
An IAM user is like an employee with a work ID — they can log in and perform tasks based on their permissions.

{
  "UserName": "JohnDoe",
  "Permissions": ["ec2:StartInstances", "ec2:StopInstances"]
}

IAM Groups – Team Access
Instead of assigning permissions to users one by one, we can group them.
Say a company has developers and accountants.

• Developers can manage EC2 servers but not access billing.
• Accountants can view billing but not manage servers. You see?

{
  "GroupName": "Developers",
  "Permissions": ["ec2:StartInstances", "ec2:StopInstances"]
}
{
  "GroupName": "Accountants",
  "Permissions": ["billing:View"]
}

IAM Roles – Temporary Access for Services
IAM roles are like guest passes—temporary permissions are given to services instead of people.
Say a delivery driver gets access to your home’s front gate but not the entire house.
Similarly, if an EC2 instance needs to read from an S3 bucket, it can assume a role.

{
  "RoleName": "S3ReadOnly",
  "Permissions": ["s3:GetObject"]
}

Best Practices for IAM Security

• Enable Multi-Factor Authentication (MFA) – Like adding a fingerprint scan to your password.
• Use IAM Roles for AWS services instead of storing credentials in code.
• Regularly review and clean up old users and unused permissions.
• Follow the Principle of Least Privilege (PoLP) – Give only the necessary permissions.
• Use AWS IAM Access Analyzer to check for security risks.

AWS IAM is like a security guard for your cloud resources. It ensures that only the right people (or services) have access to the right things. By using IAM users, groups, roles, and policies wisely, you can keep your AWS environment secure and well-managed.

Just like you wouldn’t give everyone in town the keys to your house, don’t give excessive permissions in AWS!