Here is what I read in an exam essay regarding the definition of functional and non-functional requirements:
- Functional requirements are those features that are needed for making your system function.
- Non-functional requirements are features that prevent the system from functioning.
Ok, what to say? Maybe you should add some functional requirements to your mind…
As a reference, you could simply go on wikipedia and find out the actual difference between functional and non-functional requirements.
Marco Brambilla 