Identical to the original text. Quotations match the source document word for word and must be attributed to the original author.
Putting a passage from the source material into your own words. A paraphrase is generally shorter than the original passage. A paraphrase must also be attributed to the original source.
Putting the main idea(s) into your own words, including only the main point(s). Summaries are significantly shorter than the original text. Once again, the summarized ideas must be attributed to the original source.
What's the difference?
Length and precision.
What is the same?
Every one of these requires that you cite the original source.
Still confused? Here's an example.
The original passage:
Students frequently overuse direct quotation in taking notes, and as a result they overuse quotations in the final [research] paper. Probably only about 10% of your final manuscript should appear as directly quoted matter. Therefore, you should strive to limit the amount of exact transcribing of source materials while taking notes. Lester, James D. Writing Research Papers. 2nd ed. (1976): 46-47.
A legitimate paraphrase:
In research papers students often quote excessively, failing to keep quoted material down to a desirable level. Since the problem usually originates during note taking, it is essential to minimize the material recorded verbatim (Lester 46-47).
An acceptable summary:
Students should take just a few notes in direct quotation from sources to help minimize the amount of quoted material in a research paper (Lester 46-47).
A plagiarized version:
Students often use too many direct quotations when they take notes, resulting in too many of them in the final research paper. In fact, probably only about 10% of the final copy should consist of directly quoted material. So it is important to limit the amount of source material copied while taking notes.
This example has been classed as plagiarism, in part, because of its failure to use any citation. It also uses exact phrases from the original passage without using quotation marks.
The information above comes from Purdue University's Online Writing Lab (OWL): Quoting, Paraphrasing, and Summarizing, written by Dana Lynn Driscoll, Allen Brizee.
Need more practice? This tutorial
from Cornell University will really challenge your analytical skills!