When using evidence from outside sources to help make your own claims, you will need to decide whether you want to paraphrase, summarize, or directly quote from the original source.
When you paraphrase, you put an author's idea into your own words, using your own sentence structure. Generally, paraphrasese are about the same length as the original text, but they give you the opportunity to organize the information in a way that will help the reader see how it applies to the point you're trying to make. You will want to use paraphrasing when you're trying to capture an author's idea but don't need to repeat his/her exact words. When you paraphrase, be sure to represent the original concept fairly and objectively. When you paraphrase, you need to cite the source using an appropriate citation style (MLA, APA, Chicago, etc.), so that your reader knows that the idea you're paraphrasing comes from somewhere else.
When you summarize, you provide a condensed restatement of an author's main idea(s), using your own words. Since summary is focused only on the important information from a source, it's shorter than the original. Often you may need to summarize an example from an author before you move into specific details or quotes that you want to deal with fully in your own work. When you summarize, you need to cite the source using an appropriate citation style (MLA, APA, Chicago, etc.)
When you quote, you provide the exact words of a source. You must indicate that the words come from elsewhere by placing quotation marks at the beginning and end of the quoted passage. If you need to slightly change the wording of the quote to make it more understandable, use square brackets around any words that you change. When you quote an outside source, you need to cite the source using an appropriate citation style (MLA, APA, Chicago, etc.)
In general, much of the evidence that you use from your sources can be paraphrased, especially when you're trying to convey main ideas rather than exact phrases of the authors. When you're borrowing facts or statistics from an outside source, for example, you can often paraphrase the information. Paraphrasing is often easier to work into your own paragraphs, since this method gives you more control over how the ideas are stated and connected.
In contrast, quoting works well when you want to repeat, exactly, a key concept from an authority. Quoting is also a good idea when an author explains a complex relationship so clearly that you feel a paraphrase would be more wordy or confusing than the original. Also, when you choose to quote from a source, there should be a key word or concept in the quote that you intend to use in your analysis, as you work to explain how the quote helps you advance your own argument.
Novice writers often rely too heavily on long sections of quoted material. Rather than inserting lengthy quotations into your writing, read through the source material closely to identify the key claims and concepts. Then, quote only those key ideas and use paraphrasing and summarizing to flesh out the rest of the context that is necessary for those key ideas to be understandable to your readers.