Direct electric action is one of various systems used in pipe organs  to control the flow of air (wind) into the organ's pipes when the corresponding keys or pedals are depressed. In direct electric action, the valves beneath the pipes are opened directly by electro-magnet solenoid

Solenoid

A solenoid is a coil wound into a tightly packed helix. In physics, the term solenoid refers to a long, thin loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electric current is passed through it. Solenoids are important because they can create...

s, while with electro-pneumatic action

Electro-pneumatic action

The electro-pneumatic action is a control system for pipe organs, whereby air pressure, controlled by an electric current and operated by the keys of an organ console, opens and closes valves within wind chests, allowing the pipes to speak. This system also allows the console to be physically...

, the electro-magnet's action admits air into a pneumatic or small bellows which in turn operates the pipe's valve.

Other types of actions used in pipe organs are tracker action

Tracker action

Tracker action is a term used in reference to pipe organs and steam calliopes to indicate a mechanical linkage between keys or pedals pressed by the organist and the valve that allows air to flow into pipe of the corresponding note...

, using mechanical linkage of rods and levers, and tubular-pneumatic action

Tubular-pneumatic action

"Tubular-pneumatic action" refers to an apparatus used in manypipe organs built during the late 19th and early 20th centuries. The term "tubular" refers to the extensive use of lead tubing to connect the organ's console to the valves that control the delivery of "wind" to the organ's pipes...

which utilizes a change of pressure within lead tubing which connects the key to the valve pneumatic.