How does the memory usage of a List<T> compare to a LinkedList<T>?

Short answer: List<T> uses a contiguous array internally, so memory is compact and cache-friendly. LinkedList<T> stores elements in nodes with extra pointers (Next and Previous), leading to more memory overhead. Therefore, List<T> generally has lower memory usage and better cache performance than LinkedList<T>, especially for large collections.

Real-world example (ShopNest)

In ShopNest, an order page loads products with List<Product> so you can Add items to the cart and access them by index. Use IEnumerable<T> when you only need to loop (for example, printing invoice lines).

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.