HashMap

A HashMap is a data structure used to store key-value pairs, similar to a real-world dictionary. It allows quick access to data by using a unique key to find its associated value. Internally, it computes a hash code from the key—a sort of digital fingerprint—that determines where the value is stored. This efficient lookup process means you can retrieve, add, or update data rapidly without searching through all items. HashMaps are widely used in programming because they optimize data retrieval, making processes faster and more efficient when handling large amounts of data.