Wikipedia articles must not contain original research. On Wikipedia, original research means material—such as facts, allegations, and ideas—for which no reliable, published source exists. This includes any analysis or synthesis of published material that reaches or implies a conclusion not stated by the sources. To demonstrate that you are not adding original research, you must be able to cite reliable, published sources that are directly related to the topic of the article and directly support the material being presented. The prohibition against original research means that all material added to articles must be verifiable in a reliable, published source, even if not already verified via an inline citation. The verifiability policy says that an inline citation to a reliable source must be provided for all quotations, and for anything challenged or likely to be challenged—but a source must exist even for material that is never challenged. For example, the statement "the capital of France is Paris" does not require a source to be cited, nor is it original research, because it's not something you thought up and it is easily verifiable; therefore, no one is likely to object to it and we know that sources exist for it even if they are not cited. The statement is verifiable, even if not verified. Despite the need for reliable sources, you must not plagiarize them or violate their copyrights. Rewriting source material in your own words while retaining the substance is not considered original research. "No original research" (NOR) is one of three core content policies that, along with Neutral point of view and Verifiability, determines the type and quality of material acceptable in articles. Because these policies work in harmony, they should not be interpreted in isolation from one another, and editors should familiarize themselves with all three. For questions about whether any particular edit constitutes original research, see the No original research noticeboard. This policy does not apply to talk pages and other pages which evaluate article content and sources, such as deletion discussions or policy noticeboards.