What is the light and the button used for above the mousepad of the HP Pavilion dv6000? -

There is a blue screen looking light that is located above the mousepad in the black area around the mouse. There is also a button to the right of the blue screen looking light that if you click it, the screen thingy turns orange instead. What is this button for?

The light/button by your mousepad turns on/off the touchpad just in case you re using an external mouse.