Non-functional requirements specify?

Non-functional requirements are crucial for detailing the expectations around how a product or service should perform rather than what it does. They encompass attributes such as usability, reliability, performance, security, and scalability. These requirements provide a framework for assessing the quality and overall experience of the product, ensuring that it meets certain standards and behaves consistently under various conditions.

By focusing on the operational aspects, non-functional requirements help stakeholders understand the necessary conditions for the successful use of the product, guiding both development and evaluation processes. This focus is essential for ensuring that, in addition to delivering specific functions, the product is also user-friendly and dependable, ultimately leading to a more satisfactory user experience.