What is the difference between hash table and hash set?

The main difference between a hash table and a hash set lies in their data structures and the way they store and retrieve data.

A hash table, also known as a hash map, is a data structure that uses a hash function to map keys to values. It typically consists of an array of buckets or slots, where each slot can store a key-value pair. The hash function is used to determine the index or position in the array where the key-value pair should be stored. This allows for efficient retrieval of values based on their corresponding keys.

On the other hand, a hash set is a data structure that stores only unique values. It uses a hash function to map values to their corresponding positions in an underlying array or similar structure. Unlike a hash table, a hash set does not store key-value pairs. Instead, it only stores the values themselves. The hash function helps in quickly determining if a value already exists in the set or not, allowing for efficient membership checks.

In summary, a hash table is used to store key-value pairs, while a hash set is used to store unique values without any associated keys.