Yea, so the goals on the track are different. You want the shortest lap time. Every turn has a 'slowest point'. That point in a turn where you have to be going the slowest you will be going in the entire turn. Often just before the apex. On the street we brake before the turn to that speed..or a bit under. That gives us the margin for error for not knowing the turn exactly, or gravel and so on. On the track you know the turn and the conditions, so you don't slow down that far on entry and you trail brake up to that slowest point. That keeps your speed up longer...cuts the lap time.
And eats tires.