Keyboards and Consoles
The console has everything the organist needs to control the organ. There are two types: detached or movable and attached. The movable console is often a convenience when the room must be used for more than one function. Regardless of whether they are attached or detached, the consoles have the same kinds of controls.
The manuals are the keyboards and look exactly like a piano's keyboard. However, there are only 61 notes on the organ keyboard as compared with 88 on the piano. The pedals have 32 notes. Sometimes in consideration of space or style of organ building, an organ will have 58 notes in the manuals and 30 or less in the pedals. The majority of the organ repertoire is still playable on these instruments since the missing notes are not frequently used.
The pedalboard on most 20th century American consoles is radiating and concave. Radiating means there is more space in-between pedals at the front than there is at the back (the part near the bench). Concave denotes the distance of the pedals from the ground. The outer pedals are higher than than the center ones. Organs is Europe and older American organs have a flat and straight pedalboard. This means the outer pedals are further away from your feet than on a concave, radiating pedalboard. All the pedals are an equal distance from the floor. Today, many organs built in imitation of the Baroque style are using the flat and straight pedalboards again.

You can see in the pictures that there are also pedals above the pedalboard. These do not represent a specific note but are used to control other functions at the organ. The most common pedal is the swell shoe. The swell is an enclosed division so it is in a wooden box with vertical wooden slats which move like venetian blinds. The swell shoe controls the opening and closing of these slats. When the slats are closed, the sound is quiet and distant. As the slats open, the sound grows louder and seems to move closer. This is an important distinction from electronic organs which simply have volume pedals. When the volume pedal is fully closed, it is silent. Also, electronic organs cannot reproduce the distant sound which the swell has when the box is fully closed. Thus, the swell shoe not only controls volume but also affects tonal color.
Some organs also have a choir shoe. This is exactly the same as the swell shoe except that it controls the choir. The choir is always an enclosed division.
The crescendo pedal is rarely called for in organ literature but can be a big convenience. As it is opened, it turns on the organ's stops one by one. The order of adding the stops can be set by the organist or preset by the organ builder. The stops are switched on internally so the drawknobs or tabs will not move.
Although the different divisions are controlled through different manuals, it
is possible to combine stops from different divisions through the use of
couplers. This allows one manual to control stops from several divisions and
allows more flexibility for the organist. Couplers are labeled to indicate which
division the stops are coming from and which manual (including the pedals) will
now control these stops.
For example, the Great to Pedal coupler means that stops that stops in the Great
division will now be controlled by the pedal board. This is especially useful on
organs that only have 16' and 8' pedal stops. However, the stops on the Great
will still sound if keys on the Great manual are played.
Some organs also have a Unison coupler which disconnects the manual from playing stops on its corresponding division. In the Great to Pedal example, if a Unison coupler was turned on, the Pedal would still play stops from the Great division but the Great manual would not be able to play the stops in the Great division. When the Unison is used with other couplers, it can maximize the different combinations of stops available.
Couplers can also connect manuals at a specific range. For example, a Swell to Great 4' means that all the stops currently playing in the Swell will be copied to the Great manual an octave higher than their regular pitch on the Swell. So, an 8' flute in the Swell can be copied to the Great at 4' pitch. It will still sound at the 8' pitch on the Swell. Common ranges of these types of couplers are 16', and 4'. While this type of coupler is helpful, it is not a necessary part of the organ so you may find organs which do not have them.
Pistons are the round buttons below the keys in the manuals and the
toe studs above the pedals. They can memorize any
combination of stops and couplers which the organist chooses. General pistons
affect all
divisions of the organ. Divisional pistons only affect one division and on
many organs they do not affect couplers.
Similar to pistons are reversible which affect only one stop or one coupler.
These act as on/off switches. For example, a 32' Bourdon reversible toe stud
allows the organist to turn the 32' Bourdon on with one foot. If the 32' was
already on, pressing the reversible turns it off. Typically the organ has
reversibles for the most commonly used couplers and specialty organ stops such
as the 32'Bourdon.