There are many names that are given for what the common people call "the Foxhole". Simple Definition of fortification:
the act of building military defenses to protect a place against attack: the act of fortifying something. Military foxholes have been categorized by function. All these emplacements fall under "Fortifications".  We will address the common infantry fortifications used on the battlefields of the Battle of the Bulge. Diagrams of the most common types to the right are taken from the War Department Field Manual FM 5-15, Feb 1944. Little if nothing has changed since, and the German fortifications mirror the US.