What is a hash table?

A hash table is fundamentally a data structure used to store data in the form of key-value pairs. This means that every piece of data (or value) is associated with a unique identifier (or key), allowing for efficient retrieval through the key. When a key is provided, a hash function calculates its hash code, determining the index where the value is stored. This structure facilitates quick data access, making it generally faster than traditional data structures like arrays or linked lists, especially for search operations.

The other options describe different concepts. A linear data structure is more general and refers to structures that arrange data sequentially, such as arrays or linked lists, but they do not emphasize the key-value pairing essential to hash tables. The mention of an algorithm for sorting data pertains to techniques like quicksort and mergesort, which aren’t related to hash tables. Lastly, a file type for permanent data storage is outside the realm of data structures, focusing instead on how data is saved rather than how it’s organized in memory. This distinction emphasizes the unique role that hash tables play in data management.