A Confidentiality Agreement, also known as a Non-disclosure Agreement (NDA), is a contract by which a party receiving information from another party agrees to keep such information confidential.
An NDA is between 2 parties. A party can be an individual or a company. In Singapore, there is no legal definition of a VWO, but non-profit organisations are typically registered as a society under the Societies Act, a company limited by guarantee under the Companies Act, or as a Trust (under a trust deed or under the Trustees Act). So the NDA can be used among the two parties.