How does a SortedList<TKey, TValue> differ from a Dictionary<TKey, TValue>?

Short answer: Feature SortedList<TKey, TValue> Dictionary<TKey, TValue> Order Maintains keys in sorted order No guaranteed order Internal storage Uses two arrays (keys & values) Uses a hash table Lookup complexity O(log n) (binary search) O(1) average Insertion complexity O(n) (due to shifting elements) O(1) average Memory overhead Lower (arrays) Higher (hash buckets, overhead)

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.