It sounds like you and a friend signed what you are calling a NDA. An NDA is a legal document that establish contractual conditions for the exchange of information where a disclosing party shares confidential information with a receiving party. The NDA defines information that the parties wish to protect from dissemination and outlines restrictions on use.
Many types of information are exchanged under an NDA: ideas, know-how, process descriptions, chemical formulas, manufacturing processes, IP licensing and development, research and financial information. Depending on which party is disclosing information, NDAs may be “one-way” with one party disclosing information and one party receiving, or “two-way” when there is a mutual disclosure.
Personal information is generally not covered by a NDA and public records are never covered by an NDA.