[jQuery] Simultaneous or serial execution of commands within a function?

[Rodrigo C.]

A pretty basic question, if I have this construct:

$('#img').hover(
        function() {
                $(this).parent().parent().siblings().stop().fadeTo('slow',0.3);
                $('.popdir').hide('fast');
                $('.popdir', $(this).parent().parent()).show(500);
        }
)

will the 3 lines inside the function be executed simultaneously or
serially? Will the second line wait for the animation in the first one
to end before running?