I am a School Boy and a bit new to vb.net 2008. I want to know about Class Form and Class Diagram in simple language. Can Anyone Help me Please?
Thanks in Advance

I'm not sure what you mean when you say 'Class Form'. Are you referring to the form class? E.g. the class used to create Forms in winForms programs?

A class diagram is a text/graphical display of a class, outlining various aspects of its structure such as name, parameter types, included methods, etc.
Diagrams incorporating several classes are uses to show how software components fit together and interact.
A picture would explain it better. google images for class diagram and you'll find plenty of simple examples.