Here's an example - we recently developed a simulation model to measure the remote transmission response time of a yet-to-be-developed system. An emulation analysis would not have given us the answer in time to upgrade the bandwidth capacity so simulation was our approach. Because we were mostly interested in determining bandwidth needs, we cared primarily about transaction size and volume, not the processing of the system. The simulation model was on a stand-alone piece of software that was designed to model discrete-event processes. To summarize in response to your question, emulation is a type of simulation. But, in this case, simulation was NOT an emulation because it didn't fully represent the new system, only the size and volume of transactions.
