No one is answering what you are really asking.
Classes are just code representations of OBJECTS
let's say i had a class called CAR the whole class car is a OBJECT.
Classes have constructors (functions), and fields (variables), like a constructor in a car object would be
StartEngine()
Some fields in the object car would be:
Color
Model
That make things any clearer?
Why are some of you pasting code right and left? That's not explaining anything.