Difference between IQueryable<T> and IEnumerable<T> in EF Core.?

Short answer: IQueryable<T>: Represents a query against the data source. Query is translated to SQL and executed on the database. Supports deferred execution. IEnumerable<T>: Represents an in-memory collection. LINQ operators execute in memory. Usually results after the query has executed and data is loaded.

Real-world example (ShopNest)

ShopNest’s order service uses EF Core to save an Order and its line items in one SaveChangesAsync() call inside a transaction.

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.