What Is a Database?

Definition

• A database is a collection of information or data that is electronically stored in an ordered manner.
• The information is typically stored as binary numbers ( that is: O's and 1's) on a hard disk, floppy disk, CD-ROM, or data recording tape.
• Combinations of binary numbers (0's and 1's) can represent any kind of information.
• The information is indexed, which means that different types of information in, for example, a document are identified and the location of the information in the document and in the database is tracked.
  • Example types of information:
    • Title words
    • Author's first, middle, and last names
    • Date of publication
    • Journal in which the document was published.
    • Most words in the text of a document.

Examples

• An online library catalog
• Yahoo's collection of Web pages
• A guide to colleges on CD-ROM
• A commercial article database such as Magazine Index

Analogous Examples

• An encyclopedia
• A dictionary
• A field guide to birds
• A cookbook

A Note on the Mechanics of Database storage

• Information that is stored is typically represented by combinations of binary numbers.
• Each number (0's and 1's) are usually stored as microscopic magnetic iron-oxide particles.

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