You might be asking why you'd need to use gauge controls – after all, gauges just display a single value and you could display that value using a simple label instead of a gauge.

Gauges are better because they also display a range, allowing users to determine instantly whether the current value is low, high, or intermediate. You could use two additional labels to display the range as well as the current value, but that would make your user interface more confusing. That is why many applications use progress indicators that are simple linear gauges, instead of showing progress simply as a label.

Gauges are also more visually attractive than simple labels (or sliders or scrollbars), and that adds value to your applications.