emulation 与 simulation 的区别

You want to duplicate the behavior of an old HP calculator, there are two options:

1. You write new program that draws the calculator's display and keys, and when the user clicks on the keys, your programs does what the old calculator did. This is a Simulator

2. You get a dump of the calculator's firmware, then write a program that loads the firmware and interprets it the same way the microprocessor in the calculator did. This is an Emulator

The Simulator tries to duplicate the behavior of the device.
The Emulator tries to duplicate the inner workings of the device.

引自：http://stackoverflow.com/questions/2174638/whats-the-difference-between-emulation-and-simulation