Developers on DEV Community unpack the building blocks of AWS Identity and Access Management (IAM). Core components include User identities, Group collections, temporary Role credentials via STS, and JSON Policy documents that define permissions. A quick distinction separates authentication—verifying who you are—from authorization, which governs what actions you may perform.

The guide dives into three policy types—AWS Managed, Customer Managed, and Inline—each expressed in a standard JSON schema with fields like Effect, Action, Resource, and optional Condition. Security best practices stress least‑privilege access, swapping long‑term keys for roles, enforcing MFA, rotating credentials, and preferring managed policies over custom inline rules.

Practical labs walk readers through creating a Developer group, attaching the AmazonS3ReadOnlyAccess policy, and enabling MFA, then provisioning an EC2 instance that assumes a role to list S3 buckets without embedded keys. Extending the pattern, developers can grant Lambda access to DynamoDB, set up cross‑account roles for CI/CD pipelines, and keep credentials out of code.