What is the differance beween soldering propane and cooking propane.?

I think is is the same gas. I have seen small, table-top gas grills that use the small, torch-size (non-refill) propane cylinders. They also make soldering torches that run off a regular bar-b-cue tanks. Of course, there is a hose from the tank to the torch head, you don't have pick up the tank.