Amazon S3 Cheat Sheet Hub

Amazon S3 is the most universally used AWS service and one of the highest-weight topics on SAA-C03, SCS-C02, and SAP-C02. Its apparent simplicity hides enormous depth: eleven storage classes, multiple encryption options, granular access control (bucket policies, ACLs, presigned URLs, S3 Access Points), lifecycle rules, versioning, replication (CRR and SRR), event notifications, and integration with virtually every AWS data service.

The S3 service cheat sheet covers the core concepts: bucket naming rules, object size limits (5 TB per object, 5 GB per PUT), the strong consistency model (since December 2020), storage classes and their retrieval SLAs, multipart upload thresholds, and the S3 Select/Glacier Select query capability. It also covers the exam traps most candidates miss: the difference between S3 Standard-IA and S3 One Zone-IA minimum storage durations, Glacier Instant vs Flexible vs Deep Archive retrieval times, and Intelligent-Tiering monitoring costs.

The storage class comparison cheat sheet is essential for any exam — S3 Standard vs IA vs Glacier vs Intelligent-Tiering puts all eleven classes side by side with cost, retrieval time, availability, and minimum duration in a single table. The S3 vs EBS vs EFS vs FSx comparison resolves the most common storage architecture decision: object vs block vs file storage, and when each applies.

For security and compliance scenarios (heavily tested on SCS-C02), focus on S3 Block Public Access settings, bucket policies vs IAM policies, VPC Gateway Endpoints for private S3 access, S3 Object Lock (WORM), and MFA Delete. These appear on almost every security-focused exam question involving data storage.

S3 is also the foundation of the AWS analytics stack — Athena queries S3 directly, Glue catalogs S3 data, EMR reads from S3, and Kinesis Firehose delivers to S3. Understanding these integrations is critical for DEA-C01 and any analytics architecture question on SAA-C03.