What are Epics and how do they relate to User Stories?

Short answer: Epics: Large, high-level features or initiatives that are too big for a single Sprint.

Explain a bit more

Broken down into User Stories for implementation. Relationship: Epic → Multiple User Stories → Tasks (optional) Example: Epic: “User Account Management” User Stories: As a user, I want to register with email. As a user, I want to log in with my credentials. As a user, I want to reset my password. Each of these stories can be completed in a separate Sprint and delivered incrementally.

Real-world example (ShopNest)

Agile for ShopNest means ship a thin checkout slice every sprint, get feedback, then improve—not a 6-month big-bang release.

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.