I'm writing some documentation in a project in a tool. In this tool of mine, and write in specific area, I have here use Case, Business Rule, N-Diagram Types, and Functionality and Functional Requirements.So I got me wondering, Are there differences between Functionality and Functional Requirements?In my vision, a Functionality a implementation of a Functional Requirement, is it correct? What other differences one can find between them? 
Are there differences between Functionality and Functional Requirements
terminology;documentation;requirements