[lacker]

Some operations are basic enough that theoretically you can build any other operation out of them. “NAND” is commonly used as an example but in practice “nand” doesn’t really map to how people think. Conditionals are another one. They are a bit more complicated in a sense (three inputs rather than two) but they map better to how people think so people actually use them in practice.

So Turing completeness is basically two things. 1: the ability to compose an arbitrary number of conditional statements. 2: the ability to keep computing recursively, until some output is true.