What is a citation? What is a bibliographical reference? What is a reference?
They are one and the same and can be defined as follows:

  A citation is a short, multi-part description of a specific information source.
  A citation provides the necessary information to find the cited source.
  A citation is used to give credit to the sources you use to create an intellectual work.
      [adapted from Kansas State University Libraries]

Below are examples of the two most common types of citations, citations for books and journal articles:


I. Articles (in magazines, journals, newspapers)

Here is a reference to a journal article as found in an online database:
Here is a citation of the same article based on the APA style guide:

Apostolou, N. G., Crumbley, D. L., & VanDenburgh, W. M. (2004). Ignore footnotes at your peril. The Forensic Examiner, 13 (1), 29-35.

 

KEY:

Author(s) of article
Title of article/book
 Title of magazine, journal, or newspaper
Volume and issue (not for newspaper articles)
Year of publication
Page numbers

 

II. Books

Here is a reference to a book found in an online catalog:

Here is a citation of the same book based on the MLA style guide:

Zerby, Chuck. The devil's details: A history of footnotes. New York: Touchstone, 2003.
  KEY:

Author(s) of book
Complete Title of book/article
Place of publicaton
Publisher
Year of publication