If you use someone else’s idea, cite them. If you use someone else’s words, use quotation marks and cite them.
How to Paraphrase:
To avoid plagiarism, you have to change more than a few words. It has to be your thoughts about the author's ideas, and the author needs to cited.
Paraphrasing, summarizing, and plagiarizing on Purdue University’s OWL.
What is plagiarism?
“To steal and pass off (the ideas or words of another) as one's own : use (another's production) without crediting the source.”
Plagiarism. In Merriam-Webster Online Dictionary (2010). Retrieved from http://www.merriam-webster.com/dictionary/plagiarism
Types of plagiarism