What Are The Functional And Non Functional Requirements?

What Are The Functional And Non Functional Requirements? Functional Testing like System, Integration, End to End, API testing, etc are done. Non-Functional Testing like Performance, Stress, Usability, Security testing, etc are done. Usually easy to define. What are examples of functional requirements? Business Rules. Transaction corrections, adjustments, and cancellations. Administrative functions. Authentication. Authorization levels. Audit