The CPU or Central Processing Unit is like the brain of the  computer.  It takes in numbers and spits out returned  information to the program.  Think of its a a math wiz that can  solve almost any problem given a the right amount of time.  With out it the computer would not run.  The CPU Unlike a  Human Being does not do its math by knowing theUsing  Decimal.  It uses a much simpler method called Binary A  Number base that uses only two numbers One and Zero.     The way It receives its data Is literally in an on or off signal  that can be translated to mean One or Zero.  After the CPU  Receives It's data it steps through it like answering a series of  math questions.  The CPU does not know what the data will  become it just returns Answers to the Questions it is asked.