Two Panzer IIIs in 1941
A panzer was a tank used by Germany during World War II. Although the word just means "armored vehicle" in German, the term "panzer" was used almost exclusively when describing the Wehrmacht's armored forces. German armored forces were called "Panzerarmee"s or "Panzer divisions", and Heinz Guderian wrote a 1937 book on armored warfare called Achtung Panzer!, which provided the standards set for Nazi Germany's tanks.