What are the types of relationships in a database?

Short answer: One-to-One (1:1): Each row in one table is linked to one row in another table. One-to-Many (1:M): A row in one table can be linked to many rows in another table. Many-to-Many (M:N): Rows in one table can be linked to many rows in another table and vice versa. This often requires a junction table.

Real-world example (ShopNest)

ShopNest’s SQL Server database stores customers, products, and orders. Good indexes and clear foreign keys keep checkout queries fast and safe.

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.