I/O

      I/O is the acronym for Input – Output. 

      In the world of computer science the abbreviation “IO” has been used to refer to the interm-communication between an information processing system. This is all just a fancy complicated way of saying how data looks going into an algorithm VS. how it looks coming out of it.

example:
   A high level example of IO can be though of at this:
Y = input = 1,2,3,4
Z = output = 10
= = algorithm 

Y = Z
Y = 10
1,2,3,4 = 10

So the question becomes, how does the algorithm work?

We know that the Y is some combination of the numbers 1,2,3,4. We also know that the output produced is 10. Using these knowledge points we can deduce that the algorithm works by simply adding together the input.