A non-isclosure agreement (NDA) (often known outside of the United States as a confidentiality agreement; occasionally called a confidential disclosure agreement or CDA, or secrecy agreement), is a legal contract between at least two parties that outlines confidential materials or knowledge the parties wish to share with one another for certain purposes, but wish to restrict from generalized use. In other words, it is a contract through which the parties agree not to disclose information covered by the agreement. An NDA creates a confidential relationship between the parties to protect any type of trade secret. As such, an NDA can protect non-public business information.