There is no difference between a non-disclosure agreement (NDA) and a confidentiality agreement. Non-disclosure and confidentiality agreements protect confidential information from being shared with third parties.
In other words, these documents’ titles come down to preference because they both serve the same legal function. Some other names people use interchangeably with confidentiality and non-disclosure agreements include:
Secrecy Agreement
Confidential Disclosure Agreement (CDA)
Proprietary Information Agreement (PIA)
You may see a non-disclosure or confidentiality clause in other legal documents. For example, most independent contractor agreements outline the terms of a project and include a clause stating that any information shared is confidential.