Which data structure uses a "hash function" to store and retrieve data?

Answer: Hash Table

Explanation: Hash tables use a hash function to map keys to indices in an underlying array, allowing efficient storage and retrieval of values by key.

• A hash function converts a key into an index where the value is stored.

• Collisions (different keys mapping to the same index) are handled by methods such as chaining (storing a list at each bucket) or open addressing (probing for another slot).

• Average-case time complexity for lookup, insertion, and deletion is O(1); worst-case can degrade to O(n) if many collisions occur.

• Common uses include implementing dictionaries/maps, sets, and caches where fast key-based access is required.