A regiment is a military unit. Its role and size varies markedly, depending on the country, service, or specialisation.
Romanian 27th Infantry Regiment in front of the Hungarian Parliament in 1919
The Royal Regiment of Fusiliers on parade in England
Regimental badge of the Scots Guards.
Personnel of the 154th Preobrazhensky Independent Commandant's Regiment during an exhibition drill.
A battalion is a military unit, typically consisting of up to 1,000 soldiers. A battalion is commanded by a lieutenant colonel and subdivided into several companies, each typically commanded by a majo
Regiment
…a leader who was often also the feudal lord in capite of the soldiers. Lesser barons of knightly rank could be expected to muster or hire a company or battalion from their manorial estate. By the end of the 17th century, infantry regiments in most European armies were permanent units, with approximately 800 men…
Australian 11th (Western Australia) Battalion, 3rd Infantry Brigade, Australian Imperial Force, posing on the Great Pyramid of Giza on 10 January 1915
1980s Soviet tank battalion and company
1980s Soviet 122 mm artillery battalion
Latvian platoon at Camp Lejeune