To imitate one system with another,primarily by hardware,so that the imitating system accepts the same data,executes the same computer programs,and achieves the same results as the imitated system.

• 主要通过硬件把一个系统模拟成另一个系统，这种模拟应使模拟系统与被模拟系统接收相同的数据，执行相同的计算机程序，获得相同的结果。