What is Clown?
Many people believe that a clown and clowning is only about being funny or a 'childrens entertainer in a circus'. Here are some other definitions to stretch your mind.

One who wears the red nose.

One that extracts emotions from a crowd. Not just just laughter.

A performer that walks the line between heaven and hell.

How Many?
from "the Mirthful Faces of Roger C. Way Professional Family Entertainment" page.

Classic Whiteface    
Boss or Straight Whiteface    
Grotesque Whiteface
Auguste    
Tramp/Hobo    
Character Clowns

What makes a clown a clown?
There are no right or wrong answers.