What are the differences between Functional Testing and Non Functional Testing, why are they both important, and what are they used for?
Users are blind to the underlying aspects of software and wholly unconcerned with it. This is one reason why you should bother with User Interface Testing.
What are Functional ReQuirements, and how are they different to Non Functional Requirements? Why do I need both Functional and Non Functional Requirements?
Basically, Non-functional requirements describe how the system works, while functional requirements describe what the system should do. Read more for more info.