What is your definition of childhood? In your answer, please include duration, nature, and limitations of childhood. That means when...

What is your definition of childhood? In your answer, please include duration, nature, and limitations of childhood. That means when does childhood start and end (duration)? When do you become an adult? What are children like (nature or general personality), and what are some of the things to which children should or shouldn't be exposed (limitations)? 

Your posting should be at least 300 words (but you can write more if you feel that you need to in order to answer the question). Please post your response directly to the discussion area -- DON'T submit it as an attached file.