I have a 15 speed bike. What does the left speed changer mean?

Question

On the right side there are numbers 1-5, those are 5 different gears right? When I switch the numbers, I feel the gears changing. I suppose 1 is the smallest? One is the easier one and 5 is harder to pedal.

The left side is confusing. Its got the letter "L" and then a bunch of lines to choose from, and then after all those lines there is the letter "H". Anybody know what that means?

Answer 1

You should see three sprokets on the front, L is for the Low setting, I'm guessing the smallest sproket, M is the medium, but it is the Middle sprocket and H is the High.  

The bigger one is the easiest to peddle.

Answer 2

The left gear shift moves the chain between the two cogs in the front.  L means low, H means high, referring to speed.  When the gear shift is on L, the chain is on the smaller cog, and the bike is easier to pedal.  When the gear shift is on H, the chain is on the larger cog, and it is more difficult to pedal.

Answer 3

L would stand for "Low" and would refer to the smallest chainring (the 3 rings by the pedals). As you can probably guess, H is for "High" the smaller the chainring, the easier/less resistance there is, which is good if you encounter a steep hill.

Therefore Low - 1 would be the lowest and H - 5 would be your highest gear.