Emulator

An emulator is a piece of hardware which exactly duplicates the functionality of another piece of hardware.

Unlike simulators, emulators usually have an emphasis on duplicating exactly the device's external interface and behaviour, so that they may 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.