In brief, Fast Draw is the art of reacting to a signal, drawing, firing, and hitting a target with a single action revolver using a 'full-powder' blank or wax bullet projectile.
To break that down, the timing clock gives the shooter a random two to five second delay before turning on the target light. Until that light comes on the shooter is not allowed to begin their draw or have their finger in the trigger guard. When the light comes on the shooter grabs the gun, draws it out of the holster, cocks the hammer with his thumb or 'fanning' hand, and pulls the trigger to fire the gun at the target.
The target has a micro-switch or impact sensor on it that stops the clock. When blanks are used, the target is either a four or nine inch balloon shot from a distance of eight to twelve feet. Wax bullets are fired at steel plate targets at distances up to fifteen feet.
Although this may not sound like a great distance, it should be remembered that this sport is attempting to duplicate 'gunfighting' accuracy. In other words, the ability to draw, fire and hit a target as fast as possible at close range. I can tell you from personal experience that when you're trying to do all this in under a quarter second, including reaction time, it's a lot harder than it sounds.