Bicycle "High and Low" on controls?

Question

On my bicycle there are two controls on the handlebars, one is from switching between gears, (1-6), and on the left handlebar, there's a little control that you can be turned from H to L (im assuming it means high and low), what does this do?

Answer 1

Yes, it means High or Low.

The controls on the right are for your rear derailleur, it shifts the gears on your rear wheel.

The controls on your left are for the front derailleur, that shifts the gears by your feet.

There are anywhere from 6-9 gears on the rear, and 2 or 3 on the front. This is just to give you more options for going up or down hills, tougher or easier, faster or slower.