Storz is a type of coupling invented by Carl August Guido Storz in 1882. It was also referred to as a “sexless coupling”, i.e. connection without gender, because rather than having one end male threaded and one female threaded, they have identical ends that can be joined together. It was also called free hermaphrodite or bi-directional connection..
A Storz coupling is made by joining two connections so that the hooks of each should be to fit into the slots of the flange of the other. Then they are rotated in opposite directions until they lock together. This creates a watertight connection between the internal seals. A special wrench is then used to tighten the joint of the two parts in contact.
Guido Storz also patented his coupling in Switzerland in 1890, and it soon became a standard for fire hydrants throughout most of Europe.
The main advantage of using Storz couplings is fast connection: generally, a pair can be connected with a 1/4 turn whereas with threaded fittings you need to make several revolutions of tightening to build a strong connection.
This link has quickly conquered the European market for fire hose systems, and is now the standard in the U.S. market for most applications with large diameter pipes.