You are probably thinking of the "Enigma" cipher machine. It was electro-mechanical device used to convert messages in to & out of codes. There were many different codes, and several versions of the Enigma machine. Not all German codes used the Enigma, however it is the most famous one discussed now.
you mean how they communicate in battlefield/combat?
They used sounds like: Flash...... Thunder.
example: an American soldier is in a Forrest alone or with two. He heard a sound and he don't know if it is a German or American(he cant see him, behind an other tree or something) he can say: Flash. If it was an American in that Forrest he know what to say back: Thunder.
If an American soldier scream Flash and if it was an American he knew what to say back: Thunder.
And they used click-clacks. A thing you press and it makes a click-clack sound. every soldier had that thing.
Guns
The primary duty of the Navajo Code Talkers was to use their language to communicate with the commanders and the troops and Naval Ships. Their language was not all in written form and they did not have words like bomb, ship, ammunition, etc. They used words that would describe something: for example bird for plane or eagle for bomber (made up since the code is classified still and used still). They were also fighters and Morse code senders on radios. They used many forms of radios. There was a Choctaw Code in World War 1 and that is where they got the idea to use the Navajo language since the Japanese could not understand it.
It was used for code breaking. I've seen it at a museum, it's the size of a small house!
The name of the code is Bushido
Officers used brass or nickel whistles to communicate to their soldiers in the heat of battle usually over machine gun fire and artillery fire. They would use the whistle at first to send the soldiers 'over the top' and then generally have signals like 2 blows for right and 1 for left according to how the battle was taking shape as well as if need be to signal retreat.
Languange
Languange
Code talkers were Native Americans who served the United States in World War II by using their native languages to describe artillery, armaments, troop movements and so forth. This scheme allowed the war-time commanders to communicate through the code talkers with the presumption that the 'code' in use would never be deciphered. They were correct: the code used by the code talkers was never 'broken'. Read more, below.
They use morse code.
yes only ponies and unicorns can use Morse code with an apple
It is known as the binary code.
Why would a ghost find it easier to tap out a message in Morse code, instead of using the spooken word?
This is a code that computer programmers use to better communicate with computers. Because computers operate on a binary code system that is difficult for humans to understand, a code that made communicating with computers easier.
You can use Morse code to communicate messages by representing each letter with a series of dots and dashes. For example, "SOS" in Morse code is "... --- ...", which is the universal distress signal.
Depending on the type of support supplied to you there, you may be able to use e-mail or INMARSAT or ham radio to communicate, generally, all over the world.
Guns
They use Gmail, an email website to Gmail chat with their other friends who have gmail. They use IM programs. They use Facebook, myspace and Twitter to communicate with known and unknown people.