Possible Duplicate:
Javascript: var functionName = function() {} vs function functionName() {}
Is there any difference between these two ways of declaring a function?
Possible Duplicate:
Javascript: var functionName = function() {} vs function functionName() {}
Is there any difference between these two ways of declaring a function?
They are both anonymous functions, only one is assigned to a variable named x.
I think you may be trying to refer to what is known as function expressions and function declarations.
 
    
    x = function(a, b, c){} assigns the function to the alias x so you would execute it using x(a, b, c). The second is an anonymous function that would not be accessible after the place that it was declared as it is not assigned to anything.
