The "2nd" button stands for 2nd Start, which means it starts in 2nd gear instead of first. Could be useful if you're in a low traction condition where the tires are spinning.
The Power button changes the shift pattern to get better use out of the power band (read, less fuel economy). Could be useful if you're towing.
Your owners manual should cover this too.
Rookie
I wish to thank you for your nice explain.Rgds.
az999z