Every application ends up storing its data somewhere. But open the AWS console and the database category alone lists a whole row of names — RDS, Aurora, DynamoDB, ElastiCache, Redshift. At first glance it's easy to think, "Isn't one database enough?" Yet both on the exam and in real work, the core skill is choosing which database is right for this particular data.
Today the goal isn't to memorize five headline database services — it's to build a mental picture of what problem each one was born to solve. Once that picture clicks, the answer falls out naturally in scenarios like "customer order data," "temporary shopping-cart storage," or "a month's worth of sales analysis."