There is a huge difference between an NDA and a patent. The patent is a federal document utilized to protect and enforce the exclusivity of an idea. An NDA is a contract between two people or a person and an organization. The intent of the NDA, depending on the state, is to limit competition or the dissemination of trade strategies/secrets. The intent of the patent is to enforce the protection of a unique idea. One focuses on contract law and the other focuses on patent law.