Torque Converter stall?

I don't get what a Torque Converter's stall is? Is it the point where the torque converter allows the engine to transfer power to the transmission?

No. the stall is the maximum revs an engine will produce when the transmission is not allowed to rotate.
It works this way. Hold your foot on the brake really firmly. Put the car in drive and mash the gas pedal to the floor. Use the brake so the car will not move. The maximum revs the engine produces is the stall speed. The more power the engine has, the higher the stall speed.