A paraphrase typically explains or clarifies the text that is being paraphrased. For example, "The signal was red" might be paraphrased as "The train was not allowed to proceed." When accompanying the original statement, a paraphrase is usually introduced with a verbum dicendi — a declaratory expression to signal the transition to the paraphrase. For example, in "The signal was red, that is, the train was not allowed to proceed," the "that is" signals the paraphrase that follows.
A paraphrase need not accompany a direct quotation, but when this is so, the paraphrase typically serves to put the source's statement into perspective or to clarify the context in which it appeared. A paraphrase is typically more detailed than a summary.
One feature of a paraphrase is that it preserves the essential meaning of the material being paraphrased. Thus, the (intentional or otherwise) reinterpretation of a source to infer a meaning that is not explicitly evident in the source itself qualifies as "original research," and not as paraphrase.
Unlike a metaphrase, which represents a "formal equivalent" of the source, a paraphrase represents a "dynamic equivalent" thereof. While a metaphrase attempts to translate a text literally, a paraphrase conveys the essential thought expressed in a source text — if necessary, at the expense of literality. For details, see "Dynamic and formal equivalence."