Torque and Horsepower
The Analogy: You're a rookie engineer on a new leading-edge ground-busting technology called a coal-fired steam locomotive. (You can hear the heavy investors lining up.)
Horsepower: the amount of coal per minute
Torque: the amount of coal per shovel
RPM: the number of shovels per minute
The Formula: Horsepower = Torque x RPM / 5252
The amount of coal you shovel per minute equals
the amount of coal per shovel x the number of shovels per minute
(5252 is just a conversion factor depending on what units you are using. Sometimes people use 5250.)
To get the same HP
you can use big shovels + a few shovels per minute
or small shovels + a lot of shovels per minute.
Horsepower=how many horses do you have?
Torque= how big is each horse?
(RPM=how many horse steps per minute?)
Watts = Volts x Amps
Horsepower is the work
Torque is the force
Horsepower and Torque are not really opposites. They are in fact equals. In any particular engine, you have some Horsepower and some Torque and consequently your engine has some characteristics: good speed and good pull. Of course, one major key to the puzzle is the RPM, but that...like the gearing and the energy efficiency and the polluting emissions and the government...is another story....