Non-piped organs such as the harmonium or reed organ make sound by blowing air (either with breath or bellows) to move a vibrating reed in a frame.
Digital or electronic organs employ loudspeakers to create sound waves that mimic those made by windblown pipes. They do this by coding into digital form musical tones or shapes recorded from windblown pipe organs. Due to their range and portability, the use of digital keyboard or synthesizers has found their way into popular music.
Mechanical organs play by themselves after a crank or clockwork driven by weights or springs is activated by a musician.
Pipe organs have been around for a long time, with their predecessor, the water organ, played throughout the ancient Greek and Roman worlds during races and games. From the Byzantine Empire, the use of organs spread into Western Europe where the instrument was used prominently in Catholic liturgy because of its ability to fill a larger space, such as a cathedral, with sound. Today, the organ continues to be used in church worship (either as a solo instrument or as an accompaniment to a choir), as well as in secular settings.
The organ, though it looks like a piano because both have keyboards, can actually play a versatile range of sounds due to its number of "ranks" (voices) that can be combined with others to produce a variety of reed and woodwind instrument sounds. The pipe organ is often custom-designed so it maximizes its performance in relation to its acoustical environment. This is why the bigger the cathedral, the grander the pipe organ.
The organ also calls for different music theory skills and manual dexterity, although a pianist, guided by an experienced music teacher, can easily transfer his or her skills from the piano to the organ, and enrich his or her piano-playing after developing skills on the organ.
Finding private music lessons for organs in your area may be hard, since organists are a rare breed. You have a better chance of getting music tutoring online via Live Music Tutor from experienced organ players who likely have international experience they can impart to you.