Windows has still another metaphor to the desktop metaphor to describe the organization of data on your machine. This is the metaphor of folders containing different material (e.g. data or applications).
All information stored on your computer - programs, text files, pictures etc. - are called 'data'.
The data belonging together - all letters of a text, all statements of an executable program - are stored in a file. All files on your machine are organized in folders.
The system programs My Computer, Windows Explorer or Windows NT Explorer are used to work with files and folders on your computer.