Convert result to list .Where(e => e.Department == "HR") .ToList();?

Short answer: var hrList = employees This forces query execution (immediate execution). var hrList = employees This forces query execution (immediate execution).

Real-world example (ShopNest)

ShopNest filters active products with products.Where(p => p.IsActive && p.Stock > 0) before showing the catalog.

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.