Input Validation: Sanitize and validate inputs to prevent injection attacks (e.g., SQL?

Short answer: Input Validation: Sanitize and validate inputs to prevent injection attacks (e.g., SQL? is a common interview topic in Microservices. Give a clear definition, then one concrete example.

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.