The word "datum" is considered, according to dictionary definition, to be "an item of factual information." Multiple instances of this are denoted by the plural, "data." However, although the word should strictly be used only for plural forms, it is not uncommon in contemporary usage to apply it in the singular sense, as in one piece of data or such. A "base" or storage in which data are kept, would be a data base. As with many compound phrases and terms, it is now common practice to use "database" as one word, to denote any collection of meaningful information stored in some organized fashion.

A database may consist of a single file, or of many of them. In the most general sense a database could consist of physical artifacts such as a card catalog in a library or a collection of reference texts, but it is far more...