Methods of judicial hanging
There are four methods of performing a judicial hanging — the short drop, suspension hanging, the standard drop, and the long drop.
Short drop
The short drop is done by placing the condemned person on the back of a cart, horse, or other vehicle, with the noose around the neck. The vehicle is then moved away leaving the person dangling from the rope. Prior to 1850, it was the main method used.
Suspension hanging
Suspension hanging is similar, except the gallows themselves are movable, so that the noose can be raised once the condemned is in place. This method is currently used in Iran.
Standard drop
The standard drop involves a drop of between four to six feet (1.2 to 1.8 meters) and came into use in the mid 19th century in English-speaking countries and those where judicial systems were under English influence. It was considered an advance on the short drop because it was intended to be sufficient to break the person's neck, causing immediate paralysis and immobilization (and perhaps immediate unconsciousness).
and the Long drop.