Technical Article: Horsepower vs. Torque
An excellent look at the differences between horsepower and torque and how each rating is achieved during engine development by Corvette Powertrain Engineer, Jim Ingle.
"Two views of the same measurement are involved: power and horsepower. Power is defined as "the rate of doing work" or the "rate of energy transfer". Interestingly, power cannot be measured directly....you can only measure its effects."
Link: Horsepower and Torque