Okay guys... this is kind of an embarrassing question but i'd like to know the answer.

When I push my gas pedal down, I noticed that you can push it down, and then push a little harder and it seems like you're pushing a "button" with the pedal.

What exactly does this do? I noticed that it went a little faster but i'm sure that's just because the gas pedal was pushed down.

Can anyone give me an answer?