What are non-functional requirements? Can you give examples?

Non-functional requirements describe how the system should operate, not what it should do. They define the quality, constraints, and characteristics of the system, such as performance, reliability, security, usability, and scalability.

Examples of non-functional requirements:

• The system response time should not exceed 2 seconds.
• The system should be available 99.9% of the time.
• User data should be stored with encryption.
• The interface should support Russian and English languages.
• The system should withstand a load of 1000 concurrent users.

Such requirements are important for ensuring quality and meeting user and business expectations.