I have a 2000 Chevy Tracker...?

and I am completely car illiterate. It's new and there was no manual with the car when I bought it. There is a on by my gear shift that says "N" "A/T" and "P". When you switch it to "P" the word "Power" shows up in the dash. I have NO CLUE what this is, so I was wondering if someone else did?