This is using the terminology a bit strangely. Usually a Turing machine is something that's in a complexity class above a stack automaton which is in a complexi

This is using the terminology a bit strangely. Usually a Turing machine is something that's in a complexity class above a stack automaton which is in a complexity class above a finite state machine. And then we think of computers as Turing machines because that's helpful but they are in practice finite state machines because they have a limited amount of state. But the equivalence between a Turing machine and a state machine in the article is only true if the state in the state machine can be infinite.