* Brake Horsepower (bhp): This measures the power produced by an engine *itself*, at its output shaft, before any power losses due to transmission, drivetrain, or other accessories. It's measured using a dynamometer, which essentially puts a brake on the engine's output shaft to measure the force required to stop it. This is a pure measure of the engine's capability.
* Horsepower (hp): This is a more general term and can refer to the power delivered to the wheels (wheel horsepower) or other end application. It's the power *available for use* after accounting for losses in the transmission, drivetrain, and other components. Because of these losses (friction, etc.), the wheel horsepower will always be less than the brake horsepower. If someone says "horsepower" without specifying, it's usually referring to wheel horsepower.
In short: bhp is the power the engine makes; hp is the power that gets to the wheels or to the application. Bhp is always higher than hp for the same engine and operating conditions.
