The 503rd Infantry Regiment and the 2nd Infantry Division are both formations of what military branch
2nd Infantry Division (United States) The 2nd Infantry Division ("Indianhead"; "2ID," "2nd ID", or "Second D") is a formation of the United States Army. Its current primary mission is the defense of South Korea in the initial stages of an invasion from North Korea until other American units can arrive. There are approximately 17,000 soldiers in the 2nd Infantry Division, with 10,000 of them stationed in South Korea, accounting for about 35% of the United States Forces Korea personnel.
Panzer division The term "panzer division" (German: "Panzerdivision" ) as commonly used in English language refers almost exclusively to the armored (tank) division in the army branch of the Wehrmacht and of Nazi Germany during World War II. The panzer divisions were the key element of German success in the Blitzkrieg operations of the early years of the war. Later the Waffen-SS formed panzer divisions, and even the Luftwaffe fielded a panzer division, the Herman Goring Division. The term "Panzerdivision" is still used in today's Army of the Bundeswehr (for example 1. Panzerdivision). In German speaking countries the term is not immediately associated with the Wehrmacht as it is in English speaking nations, as the word simply means 'armored division' and has no additional connotation.