Final answer:
Functional requirements describe what a system should do, like user authentication and report generation, while non-functional requirements outline how the system performs these functions, including attributes like performance and usability.
Step-by-step explanation:
Functional requirements define the fundamental actions that must take place in a system in terms of data manipulation, processing, and operations to be performed. Examples of functional requirements could include user authentication, reports generation, data processing, and more. On the other hand, non-functional requirements (NFRs) are the standards that describe how the system performs the required functions. These include performance, security, usability, reliability, and other system attributes.
For instance, a functional requirement for a social media application would be to allow users to post updates, whereas a non-functional requirement might stipulate that the system should handle 10,000 users at once without performance degradation. In engineering and software development, both types of requirements are critical, with functional requirements outlining what the system does, and non-functional requirements describing how the system operates or constrains the solution.