What is projection (Select) and why is it useful?

Short answer: Projection transforms entities into custom shapes, e.g., DTOs. var projected = context.Products

Example code

.Select(p => new { p.Name, p.Price }); Useful for: Reducing data load. Returning only needed fields. Mapping to custom types.

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.