Documents are files belonging to a certain topic, created by an application program. They are not only text files, but involve any file types and elements. A document always consists of the content, the structure and the layout in which the content is presented.
Like files, documents can be stored under a specific name in a memory area and opened for further processing. The individual file records of a document can then be processed individually. For example, a text document may consist of a letterhead, address, letter, and footer, which together form an organizational unit, the document. In addition to the text files mentioned above, documents can also include graphics, photos, tables, applets, or videos.
A compound document is a composite document, whereby it is not further defined which components such a document has and in which form it is compound. The only thing that is certain is that a compound document is any kind of object.