By far, we have explained how the left pedal works in two major piano models and why you see keys moving in the grand piano when pressing down the left pedal. Now we are going to explain the most commonly used right pedal, the sustaining pedal ( also called a damper pedal, or a loud pedal).
The right pedal, whether from the grand or the upright model, is always the sustaining pedal and the function of this pedal is the same in both types of pianos.
When you pressed down the sustaining pedal, the damper lift rail ( a self-explanatory name) causes all dampers that are resting on the strings lifted away from the strings.
Normally, when you pressed a key without pressing down the right pedal, the damper is lifted and as soon as the key is released, the damper comes back to its original place, stopping the strings from vibrating. The corresponding outcome is that you hear the tone stopped.
But when the right pedal is pressed down and all dampers are lifted simultaneously, the strings are free to vibrate even after the keys are released. As a result, you can hear the tones are still hanging in the air after the keys been released. In other words, tones have been sustained, generating a wide diversity of sound colours.