The basic building blocks of a computer are called logical gates or just gates . Input and output values are the logical values true and false . In computer architecture it is common to use 0 for false and 1 for true.
Gates have no memory .
The value of the output depends only on the current value of the inputs. This fact makes it possible to use a truth table to fully describe the behavior of a gate. The output value is 1 if and only if all of the inputs are 1 . Otherwise the output value is 0 . It is often useful to draw diagrams of gates and their interconnections.