A Simulator is a piece of software that simulates your application on a PC (or other host system) instead of using any target hardware. Thus a Simulator has nothing to do with the ISP cable.

An In-Circuit Emulator or ICE (sometimes called just an "emulator" for short) is a piece of hardware (and associated host software) that replaces the processor chip in your target. This can be used to give access to things like ADC data but, again, has nothing to do with ISP cables.

Or perhaps you're thinking of chips like the SiLabs parts which have on-chip debug hardware - effectively giving you a built-in ICE? In this case, the cable used to access the on-chip debug hardware may also be used to program the chip...