There is some confusion, and no general agreement, about the precise difference between the terms emulator and simulator. Generally, an emulator is a unit which exactly duplicates the external, visible functionality of another unit; the term is usually used of hardware, but not always.
Since emulators usually have an emphasis on duplicating exactly the device's external interface and behaviour, they may often be used in place of the emulated device.
One common form of emulator is an In-Circuit Emulator (often called by the acronym, ICE), which is a perfect emulation of a given chip, down to the physical form, but which has a control unit attached to it which can record the operation of the emulated chip, for diagnostic and debugging purposes.
- Simulator or Emulator? What is the difference? - One good discussion of the subject