A database that automatically scales up and down based on demand and charges you only for the compute time you actually use, with no server management required. Like a pay-per-minute parking meter instead of renting a monthly parking space — you only pay when your car is there.
A seasonal e-commerce site uses Amazon Aurora Serverless to handle their Black Friday traffic spikes automatically — the database scales from 2 to 64 capacity units during peak hours, then scales back down to near-zero overnight, saving 70% compared to always-on databases.