The Dictionary object can contain items, which can be any form of data, just like a collection. However, the Dictionary object has many advantages over a collection. It allows retrieval of the key using the keys(index) syntax. It features an Exists property that determines whether a particular key exists. It allows for the changing of a key, as well as the changing of a value associated with a key. The Dictionary object is zero-based, and does not provide an enumerator.
Also, note that to use the Dictionary object, you must set a reference to the Microsoft Scripting Runtime.
For more information, look on VB's Help file under "Dictionary" and "FileSystemObject."