Professional wargaming

A wargame at the US Naval Postgraduate School (June 2018).
A wargame at the US Marine Corps War College (April 2019).

A wargame, generally, is a type of strategy game which realistically simulates warfare. A professional wargame, specifically, is a wargame that is used by military organizations to train officers in tactical and strategic decision-making, to test new tactics and strategies, or to predict trends in future conflicts. This is in contrast to recreational wargames, which are designed for fun and competition.