The Dictionary object is used to store name/value pairs (referred to as the key and item respectively). The Dictionary object is like an associative array, but with its own built-in functionality that looks after the basic tasks of storing and manipulating the data, and sizing for the required number of elements. Each item in the Dictionary object is associated with a unique key. The key is used to retrieve an individual item. We don't have to worry about which row or column the data is in, we just access it using a unique key.