What are the different normal forms (1NF, 2NF, 3NF, BCNF, 4NF, etc.)?

Short answer: ddresses a different kind of redundancy or dependency. 1NF (First Normal Form): A table is in 1NF if it contains only atomic (indivisible) values and each record has a unique identifier (Primary Key).

Real-world example (ShopNest)

Product and Category are separate tables (normalized). The order line stores product id + price snapshot—not a giant duplicated product blob.

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.