AngularJS function () vs function factory() in directive

Question

In angular I've seen directives written both as:

.directive('example', function () {
    // Code
});

.directive('example', function factory() {
    // Code
})

What's the difference between the two?

Answer 1

that is just passing in a named function rather then an anonymous one.

the same way as you can write functions as below:

var foo = function() {
    //function content
}

or

var foo = function foo() {
    //function content
}

Answer 2

function(){..} is an anonymous function.

function foo(){..} is a named function.

There is no difference, otherwise, in functionality. Named functions are better for debugging purposes.