harley upgrades

i bought an 07 softail custom about a year ago. it had 500mi. on it.
i have put about 3000 mi. on it since.
i have been hearing about stage one and stage two upgrades. as a first time harley owner can someone please explain these upgrades to me?
how do the upgrades improve the bike? what do they do for the bike?  more power?


thanks in advance,
frank  

Upgrades increase horsepower rating and torque, and there are many different steps one can take to add more horsepower, top end, exhuast system changes, Air Cleaner change,  EFI tuner, ignition, Cubic inches as part of top end.  There are many more things one can do, would ask your local Harley Dealer about it.  The downside is the possibility of more things breaking down the more you change your ride.  I have added an EFI tuner on my trike and bike, and have changed the exhaust system, which added mid range power from 40-80  

There are so many perameterswhen it comes to exhaust and performance gains. Speak to a GOOD TRUSTWORTHY shop. I work at a deaershipand I get this question all the time. Most of the time performance work is based on $$$ you have to work with and what your ultimate goal is