Paraphrasing is rewording text so that the original meaning is there but it is in a new form. Rewriting a sentence, or a whole passage, in your own words is paraphrasing. To avoid being accused of plagiarism, it is important that you don't try to pass off someone else's words as your own.
In the following paraphrase examples, the original sentence is worded differently in the second sentence so that it provides the same information but it is not a copy of someone else's words:
The key to successful paraphrasing is to use different words and a different sentence structure without changing the overall meaning of the text. Rewording a short sentence is straightforward, see Examples of Paraphrasing for help with paraphrasing longer paragraphs.
To help you decide whether you want to paraphrase a passage or quote someone directly, read our article on When to Quote, Paraphrase or Summarize.