A citation identifies for the reader the source of the origin for an idea, information, or image that is referred to in a work.   You use citations to avoid plagiarism. 

Additional Information on Citing Resources

• Purdue Online Writing Lab (OWL) Citation Guides
   
• Chicago Manual of Style:

Using Chicago Citation examples.

ONLINE GUIDE:  Chicago Manual of Style
 

• MLA:

Using MLA Citation examples.

ONLINE GUIDE:  MLA Handbook Plus