A paraphrase is a restatement of another author's writing in your own words. Paraphrasing is often the most effective way to present material you have located through your research.
Why is it so effective? Because it allows you to maintain a consistency of style and voice in the writing, while at the same time allowing you to benefit from the authority that outside sources can lend to your argument.
Paraphrasing is the best way to avoid one of the biggest complaints that instructors have about students' research writing: that it reads like a cut-and-paste scrapbook of quotations from other people. Paraphrasing shows that you are in control of your own paper; you understand what you have read and you can use it, and the authority it represents, to make a strong case.
Paraphrasing, if done correctly, can also help you avoid plagiarism in your writing. Therefore, it's important to know how to write an acceptable paraphrase. That's our next topic.