James,
I'll give it a shot although my automotive engineering classes were over 10 years ago so I'm probably a bit rusty.
Torque is rotational force or twisting. Measured in Ft-Lbs or N-m, it is an indication of the amount of force that the engine is able to generate and transmit to the wheels. In this case, the units of measurement are actually quite helpful in envisioning what torque is. Say you have a car that is rated at 200 Ft-Lbs. This means that at a distance of 1 ft from the center of a rotating shaft, it can provide 200 lbs of force. If you assume that the radius of the wheel and tire on your car is approximately 1 ft (very approximately), then you have 200 lbs of force being applied by the tire to the pavement. It is torque that pins you to your seat when the light turns green.
Horsepower is the engine's ability to produce torque over time - torque x rpm (there's also a conversion factor here to make the units work out but I don't recall what it is) and is most important in determining the car's top speed.
There's an old saying 'Torque wins races; Horsepower sells cars'. While this isn't true of all types of racing, it is definately true at the drag strip. Most important, is actually the shape of the engine's torque curve when plotted against engine speed - the flatter and more even it is, the better the car will 'pull' from all speeds and in all gears.
You also asked about the difference between hp and bhp. BHP stands for brake horsepower and I believe is a term that goes back to the original methods of measuring horsepower through the use of a hydraulic brake mounted on the engine output shaft. It is a measure of the engine's output only and does not account for losses elsewhere in the drive train. Net horsepower, which has been used here in the US at least since 1972, is measured at the drive wheels and is a much more realistic measure of the total performance of the car. HP is a general abreviation for horsepower and may refer to net or brake horsepower depending on the writer.
I hope this helps. Anyone who has additions or corrections, please chime in. As I said, it's been awhile since I dealt with this stuff regularly.
jlc
PS - James, do I gather correctly you are from NJ?