What are the key differences between Azure SQL and Cosmos DB?

Short answer: Feature Azure SQL Cosmos DB Type Relational NoSQL, multi-model Schema Fixed Schema-less Scaling Vertical/Horizontal Horizontal, automatic Consistenc ACID Multiple consistency levels (Strong, Eventual, etc.) Use Case OLTP, structured data Global apps, unstructured data, IoT

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.