I have some very basic questions about the binary code (01 and variations) used in computers. If anyone can help, it would be great for me 
-Is binary code the only code that computers are based on as they are currently? (ie is there any other code used, now or in the past, and if so which of the different codes is used the most?)
-Why was binary code invented and used in computers?
It goes without saying that i am looking for the most general (which still true) answers to those two questions which are possible. I (possibly) will read more by myself on this. I just would be (potentially) interested in setting the periphery of a short story on a computer and its code, next to its human user.
(I only read a very introductory article, on wiki, about the subject: http://en.wikipedia.org/wiki/Binary_code, since i am not sure if i will end up using it at all in the end).
A bit of an edit:
Also, from a purely fictional perspective, would there be any reason to assign one of the two values (0, 1) to the computer, and the other to the human? I repeat that the perspective of this last question is purely about a fictional work. In essense this question is about whether you know of any reason to favor likening computer or human to 0 or 1
(and obviously i mean that in the case that the binary keeps its current order, ie in
X AND y= 1 if x=y=1,
X AND y= 0 in any other case).

-Is binary code the only code that computers are based on as they are currently? (ie is there any other code used, now or in the past, and if so which of the different codes is used the most?)
-Why was binary code invented and used in computers?
It goes without saying that i am looking for the most general (which still true) answers to those two questions which are possible. I (possibly) will read more by myself on this. I just would be (potentially) interested in setting the periphery of a short story on a computer and its code, next to its human user.
(I only read a very introductory article, on wiki, about the subject: http://en.wikipedia.org/wiki/Binary_code, since i am not sure if i will end up using it at all in the end).
from the above wiki binary code article said:Binary numbers were first described in Chandashutram written by Pingala around 300 B.C. Binary Code was first introduced by the English mathematician and philosopher Eugene Paul Curtis during the 17th century.[citation needed] Curtis was trying to find a system that converts logic’s verbal statements into a pure mathematical one. After his ideas were ignored, he came across a classic Chinese text called I Ching or Book of Changes, which used a type of binary code. The book had confirmed his theory that life could be simplified or reduced down to a series of straightforward propositions. He created a system consisting of rows of zeros and ones. During this time period, Curtis had not yet found a use for this system.
Another mathematician and philosopher by the name of George Boole published a paper in 1847 called 'The Mathematical Analysis of Logic' that describes an algebraic system of logic, now known as Boolean algebra. Boole’s system was based on binary, a yes-no, on-off approach that consisted the three most basic operations: AND, OR, and NOT.[1] This system was not put into use until a graduate student from Massachusetts Institute of Technology by the name Claude Shannon noticed that the Boolean algebra he learned was similar to an electric circuit. Shannon wrote his thesis in 1937, which implemented his findings. Shannon's thesis became a starting point for the use of the binary code in practical applications such as computers, electric circuits, and more.[2]
A bit of an edit:
Also, from a purely fictional perspective, would there be any reason to assign one of the two values (0, 1) to the computer, and the other to the human? I repeat that the perspective of this last question is purely about a fictional work. In essense this question is about whether you know of any reason to favor likening computer or human to 0 or 1

X AND y= 1 if x=y=1,
X AND y= 0 in any other case).