Explanation
Non-functional requirements capture the elements that users might not directly care about but are important to support the proposed architecture and operational viability of the solution. Non-functional requirements often influence user adoption and perceived satisfaction with the solution.
Examples of common non-functional requirement types include:
Availability
Compliance/regulatory
Data retention/residency
Performance (response time, and so on)
Privacy
Recovery time
Security
Scalability
Reference:
https://docs.microsoft.com/en-us/learn/modules/work-with-requirements/4-non-functional-requirements