Well i will try to add my 2 cents, but this will be hard as :

1) this is related to ooooold physics principles I learnt in my studies
and
2) I will try to explain them in english which is not my language
and
3) I may be 100% wrong in my answer ROFLMAO

As far as I know, what needs to be understood first is that torque is a rotating force, where bhp is a straight line force (vectorial).
Basically, torque is what makes it so that it's easier to unscrew a wheel nut with a long wrench rather than with a short one : the further you are from the center of the point you want to add the force on, the bigger the force will be. (same as with home door handles for instance, works better when you push at the end of the handle rather than when you push at the center of the axle ) This is torque.

Now, with bhp... as far as i remember, what needs to be known, is what 1 BHP actually IS !
1 BHP is the force that allows to pull a weight of 75 kilograms at 1 meter above the ground during 1 second.

Now, about cars... you can't have bhp without torque, nor torque without bhp. It's just a question of RPMs (yes... rotations. Remember torque is a rotating force ).... the lower RPMs the max bhp are available at, the more torque you will have.
What is sure, is that max torque and max bhp on a car (or on everything that has an engine) are closely related and can be calculated one from the other. I can't remember the exact formula, but if you know the max bhp of a car and the rpm they appear at, you can calculate very precisely the max torque too.

Hope this helps... pretty sure this is not very clear... forgive my english mistakes