Simulation is a type of analysis proceeding through chains of events or circumstances (that is, as a matter of cause-and-effect). The term is often used when the solution of time-domain ODE’s is required to calculate an end state, or a series of intermediate states. It can, however, be used with respect to other independent variables (see, for example, Monte Carlo Simulation, which integrates over a convolution of probability density functions).
In the context of Verification Methods, Simulation is sometimes considered apart from (a peer to) Analysis. In my opinion, there is no good cause for this distinction, which could with equal rationale be claimed for any other specialized analytical processes.
Contrast with emulation.