What are the primary types of nonfunctional requirements?

Nonfunctional requirements primarily encompass performance, security, usability, reliability, and maintainability. Performance specifies how the system behaves under certain conditions, while security addresses protection against unauthorized access and threats. Usability focuses on how user-friendly and accessible the system is, whereas reliability ensures the system operates consistently over time. Finally, maintainability refers to how easily the system can be updated or repaired.