Hash Tables
They are key-value array-based data tables that allow for consistent and generally quick access to data stored in it, it works by making a hashing algorithm that turned keys into numbers, and then using this algorithm on each key-value pair, and depending on the hashed key, we put this data in it’s proper array index (ex. the key “john” may have a hashed value of 10 after passing through our algorithm, so we put the key and it’s data inside that index).
In case of collision, we usually just use some form of data collection method, like an array or a linked list or even another hash table.