Participating in academic discourse means using information that exists in other places. To do this with integrity, we choose a way to integrate and cite that information. One way to do this is with paraphrasing, or rewriting someone else’s original ideas in your own words and still citing the original source.
A word to the wise:
Changing every third word in a passage does not count as paraphrasing. You are better off quoting and citing the actual source!
Paraphrasing is similar to summarizing. Summaries only include the essential ideas of a work, while paraphrases include more details. Regardless of what you call it, you must cite the original source.
Depending on the circumstance, you may prefer to use an exact quote, surrounded by quotation marks.