I'd say emulation is to replicate a known behaviour of a system while simulation is to build an internal odel of a system in order to observe its behaviour. Fo

I'd say emulation is to replicate a known behaviour of a system while simulation is to build an internal odel of a system in order to observe its behaviour. For instance, a CPU emulator is only concerned with executing instructions in the same way as the actual CPU whereas a CPU simulator would be a internal model of the CPU at some level of details (e.g. transistor level) in order to observe how it behaves (which you perhaps don't know).