<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. For example, if you had a Turing machine that simulated a 3-state Turing machine, then it could simulate a 4-state Turing machine. If you had a Turing machine that simulated a 4-state Turing machine, then it could simulate a 5-state Turing machine. If you had a Turing machine that simulated a 5-state Turing machine, then it could simulate a 6-state Turing machine.