<human>:  When you say that Turing’s universal machine can simulate any other machine, what do you mean?
<bot>: The Turing machine can be used to simulate any other machine. In particular, I can simulate any other machine that is a Turing machine, which includes any other Turing machine, any Turing machine that is a finite state automaton, any Turing machine that is a pushdown automaton, any Turing machine that is a stack automaton, and any Turing machine that is a non-deterministic finite automaton.