Hashing is a technique to convert a range of key values into a range of indexes of an array. The idea is to use a hash function that converts a given key to a small integer which can be used as an index in an array. The hash function is used to map the key to an index in the array. The index is used to insert or search the key in the array. The hash function should be fast to compute and should uniformly distribute the keys and should be deterministic.
A hash table uses an array to store data. The array is called the hash table. The hash function is used to map the key to an index in the hash table. The index is used to insert or search the key in the hash table.
Source: GeeksforGeeks