Answer:
This page in a nutshell: Summarize in your own words instead of closely paraphrasing. Closely paraphrased material that infringes on the copyright of its source material should be rewritten or deleted to avoid infringement, and to ensure that it complies with Wikipedia policy. Public domain sources and CC-BY-SA-compatible sources may be closely paraphrased, and limited close paraphrasing of copyrighted sources may also be permitted as fair use. Attribution is always required.
For information on copy and pasting text, see Wikipedia:Copying text from other sources.
Close paraphrasing is the superficial modification of material from another source. Editors should generally summarize source material in their own words, adding inline citations as required by the sourcing policy.
Limited close paraphrasing is appropriate within reason, as is quoting, so long as the material is clearly attributed in the text – for example, by adding "John Smith wrote ...", together with a footnote containing the citation at the end of the clause, sentence or paragraph. Limited close paraphrasing is also appropriate if there are only a limited number of ways to say the same thing.
Close paraphrasing without in-text attribution may constitute plagiarism, and when extensive (with or without in-text attribution) may also violate Wikipedia's copyright policy, which forbids Wikipedia contributors from copying an excessive amount of material directly from other sources. Public domain material must likewise be attributed to avoid plagiarism. If the source material bears a free copyright license that is compatible with Wikipedia's licenses, copying or closely paraphrasing it is not a copyright violation so long as the source is attributed somewhere in the article, usually at the end.
The best way to prevent close paraphrasing is to understand clearly when it is a problem, how to avoid it, and how to address it when it appears.
