Copying, quoting, paraphrasing, or summarizing from any source without adequate documentation is plagiarism. But by properly citing your sources, you can avoid serious penalties and instead learn to ethically integrate source material into your own text.
Additionally, citing your sources lends credibility to your argument. If you back up your thesis with facts and ideas from scholarly sources, your argument is more persuasive.
Even when using RefWorks, you should be familiar with your citation style to make sure that your citations are correct. Not sure which style to use for your paper or project? Ask your professor!
Here are some guides to common styles: