Javascript Behaviour

Question

Just started javascript couple a days ago. Both those function outputs the same. So, what's the difference between them?

First Method:

function fakeAjax(url,cb) {
    setTimeout(function fakeLoadingDelay(){
        cb([
            "A Song of Ice and Fire",
            "The Great Gatsby",
            "Crime & Punishment",
            "Great Expectations",
            "You Don't Know JS"
        ]);
    },500);
}

Second Method:

function fakeAjax(url,cb) {
    setTimeout(cb([
            "A Song of Ice and Fire",
            "The Great Gatsby",
            "Crime & Punishment",
            "Great Expectations",
            "You Don't Know JS"
        ])
    ,500);
}

Thanks a lot in advance.