What are the functional requirements besides user story and use case?

Functional requirements include not only user stories and use cases, but also:

• System behavior requirements — what the system should do in various situations.
• Business rules descriptions — constraints and conditions affecting the operation of functions.
• Interface requirements — how the user interacts with the system.
• Data requirements — what data is entered, processed, and output.
• Validation and error handling requirements — how the system should respond to incorrect data.
• Performance and security requirements, if they affect functionality.

Thus, functional requirements are a complete set of descriptions of how the system should operate from the user's and business's perspective.