I've never played Minecraft : can someone explain ?
Logic gates are effectively the building blocks of a computer. Most transistors in a computer chip are logic gates, although other transistors serve other functions like voltage management or memory. We have billions of transistors in computer chips now. Imagine the insane amount of logic gates in them.
Using logic gates (Shown in the below), you can create an adder. It adds binary numbers. Any input of binary combinations creates an output.
Binary numbers work like this: the rightmost digit is 1, the one to the left is two, and so forth.
10 (in base 10) = 1010 (In binary)(8 + 2 in base 10)
The one below is a 3-bit adder. Max number is 3. You combine them to handle bigger numbers.
There's switches that you can use to create AND, OR, and NOT logic gates in Minecraft. So you can effectively build a computer within a computer game.