ETRM stands for Energy Trading and Risk Management. It is the branch of CTRM software aimed at the energy sector, where hourly horizons (power), complex forward curves, financial derivatives and wholesale-market regulation all come into play.
In practice an ETRM shares its architecture with a general CTRM but adds scheduling, nominations and balancing modules, and often a direct link to market platforms.
If you trade non-energy physical commodities — agriculture, nuts, metals — a general CTRM such as Granel fits better than an ETRM, which will be oversized for the job.