Non-Disclosure Agreement is a document that basically requires that the person signing the document does not disclose certain facts to anyone. Usually, an NDA will make the negative consequences of allowing the information to go public will be exorbitantly expensive as a discouragement to dislosing facts. The fact disclosure could be intentional or through fault of negligence. For example, if you have confidential files on a computer without a strong password, and that computer gets stolen – then the person will be held responsible for any disclosure of such files.