Master-Slave Replication (Primary-Secondary):?

Short answer: One database (master) handles all writes, while one or more secondary databases (slaves) replicate the data for read queries and redundancy. Advantages: Load balancing for read-heavy applications, fault tolerance. Disadvantages: Writes are still a single point of failure.

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.