Paraphrasing is when you create your own wording of essential information and ideas expressed by someone else without directly quoting. Paraphrasing is similar to summarizing, however summaries only include the essential ideas of a work, while paraphrasing includes more details.
Since your paper should only use direct quotations sparingly, you'll probably be paraphrasing frequently. Just remember that you still need to express plenty of your own ideas. Use paraphrasing to support those ideas, and be mindful that you still need to cite paraphrased portions of your paper.