Highbar is basically correct (though he or she should have said that one is wider relative to its height, rather than saying one is wider than the other, as the width of the image is dependent upon the screen size; they will be the same width when displayed on a 16:9 screen, but a different height, unless one crops or distorts the image). As to the question of whether one is better than the other, neither is "better." They are simply different aspect ratios. Some people, of course, may prefer one aspect ratio over another, either for aesthetic reasons or one may better fit the aspect ratio of the screen one is using, but it has nothing to do with the quality of the original film or format.
