A non-disclosure agreement is a legally binding contract that establishes a confidential relationship. The party or parties signing the agreement agree that sensitive information they may obtain will not be made available to any others. An NDA may also be referred to as a confidentiality agreement.
Non-disclosure agreements are common for businesses entering into negotiations with other businesses. They allow the parties to share sensitive information without fear that it will end up in the hands of competitors. In this case, it may be called a mutual non-disclosure agreement.