"Infantry division" refers to a military formation composed primarily of infantry units, also supported by units from other combat arms. In the Soviet Union and Russia, an infantry division is often referred to as a "rifle division". A "motorised infantry" division refers to a division with a majority of infantry subunits transported on soft-skinned motor vehicles. A "mechanized infantry" division refers to a division with a majority of infantry subunits transported on armored personnel carriers (APCs) or infantry fighting vehicles (IFVs) or both, or even some other class of armored fighting vehicles designed for the transportation of infantry. Mechanized infantry divisions in Nazi Germany were called ""Panzergrenadier" divisions". In Russia, they were known as "motor rifle divisions".