Contemporary logic circuits use MOSFETs as the elements to build gates, but there are many ways to implement them. Using relays is one of them, and you can literally see how they work.

this teaching tool allows different logic gates to be wired together with patch cables. While [David] first thought to use 74-series logic circuits directly, a much more versatile solution was to ...

A collection of transistors and resistors that implement Boolean logic operations in a digital circuit. Logic gates have one or two 0 or 1 inputs but only one 0 or 1 output as in the following ...

A single digital signal has only two states - on or off. However, if you use two inputs you can double the number of possible states, to four.

An AND gate usually has two inputs. AND tells us that both Input A AND Input B have to be 1 (or ON) in order for the output to be 1. Otherwise the output is 0.

That makes the placement & optimization process clock aware. Also it provide the necessary pull/push information for clock logic while clock tree building. Clock Gate Aware Design Closure Algorithm ...