In one sentence
Use RDS for managed relational engines, Aurora for AWS-optimized relational workloads, and DynamoDB for serverless key-value access.
Key points
- RDS supports familiar engines, SQL, transactions, and joins with managed operations.
- Aurora is MySQL/PostgreSQL-compatible with distributed storage and AWS-specific scaling and availability features.
- DynamoDB is a serverless NoSQL database designed around partition keys and known access patterns.
Exam takeaway
Multi-AZ is high availability, read replicas scale reads, and DynamoDB design starts from keys and queries rather than joins.