Why is null an object and what's the difference between null and undefined?

Question

Why is null considered an object in JavaScript?

Is checking

if ( object == null )
      Do something

the

Answer 1

1. Undefined means a variable has been declared but it has not been assigned any value while Null can be assigned to a variable representing "no value".(Null is an assignment operator)

2.Undefined is a type itself while Null is an object.

3.Javascript can itself initialize any unassigned variable to undefined but it can never set value of a variable to null. This has to be done programatically.