What is the difference between char and Char?

Possible Duplicate:
What is the difference between String and string

When I run:

char c1 = 'a';
Console.WriteLine(c1);

and when I run:

Char c2 = 'a';
Console.WriteLine(c2);

I get exactly the same result, a.

I wanted to know what is the difference between the two forms, and why are there two forms?