Which best describes a hash table?

A hash table is best described as a data structure that uses a hash function to map keys to values. This means that it takes a key, processes it through a hash function, and generates a corresponding index where the associated value can be stored or retrieved. The efficiency of hash tables lies in their ability to provide fast average time complexity for insertions, deletions, and lookups, typically O(1), due to how quickly the hash function computes the index.

In contrast, other descriptions do not encapsulate the unique attributes of a hash table. A fixed-size record typically refers to structures like arrays or records in databases that have a predetermined size but do not benefit from the dynamic mapping capabilities of hash tables. A collection of ordered elements and a sequence of elements sorted by key describe data structures like linked lists or binary search trees, where the order is determined by the values themselves rather than direct key-value mappings as utilized in hash tables. Hence, the distinct method of linking keys to values through hashing sets hash tables apart and accurately defines their functionality.