What is the power drive button in my car?

I got a 99 honda passport, 2 wd. I've always seen the button there but I've never used it. What does it do, and what is this power drive meant to be used for?

It is a drive mode, where the transmission shifts a little later at a higher rpm. The car has more power/acceleration when it is at higher rpm.

From Honda:
For added convenience and ease of operation, Passport is available with a 4-speed automatic transmission (std. On EX). It features electronically controlled shifting, plus a lockup torque converter in 2nd, 3rd and 4th gears for increased fuel economy. Also, it offers selectable "Power" and "Winter" shift modes, so drivers can choose which shift pattern best meets their needs. In "Power," the gears are held longer so the engine can rev higher for better acceleration: in "Winter," the transmission starts off the line in 3rd gear, to eliminate wheel spin on slippery surfaces