Computers That Can Compute Any Computable Function

A machine that can simulate any turing machine is capable, in principle, at least, of carrying out any computation. This gives rise to the term of a machine being turing complete - as powerful as we can reasonably ask it to be. It may be impractically slow to perform these computations, and it may require huge amount of memory. But at least in principle, it would finish in a finiut number of steps. And so it is powerful enough to perform that.