World War 2, German SdKfz 234/4
The military's armored (or armoured) car (see spelling differences) is a wheeled armored vehicle, lighter than other armored fighting vehicles, primarily being armored and/or armed for self-defense of the occupants. Other multi-axled wheeled military vehicles can be quite large, and actually be superior to some smaller tracked vehicles in terms of armor and armament.
French armored car: the Charron-Girardot-Voigt 1902.
At the beginning of the twentieth century a number of military armored vehicles were manufactured by adding armor and weapons to existing vehicles. The first manufactured one was the "Motor War Car" in 1902. The Italians used armored cars during the Italo-Turkish War. A great variety of armored cars appeared on both sides during World War I and these were used in various ways.
A Rolls Royce armoured car 1920 pattern
Generally, the armored cars were used by more or less independent car commanders. However, sometimes they were used in larger units up to squadron size. The cars were primarily armed with light machine guns. But larger units usually employed a few cars with heavier guns. As air power became a factor, armored cars offered a mobile platform for anti-aircraft guns.
In 1914, the Belgians fielded some early examples of armored cars during the Race to the Sea. The British Royal Naval Air Service dispatched aircraft to Dunkirk to defend the UK from Zeppelins. The officers cars followed them and these began to be used to rescue downed reconnaissance pilots in the battle areas. They mounted machine guns on them and as these excursions became increasingly dangerous, they improvised boiler plate armoring on the vehicles provided by a local shipbuilder. In London Murray Sueter ordered "fighting cars" based on Rolls-Royce, Talbot and Wolseley chassis. By the time Rolls-Royce armored cars arrived in December 1914, the mobile period on the Western Front was already over.
Polish production AMZ Zubr
A military armored car is a type of armored fighting vehicle having wheels (from four to ten large, off-road wheels) instead of tracks, and usually light armor. Armored cars are typically less expensive and have better speed and range than tracked military vehicles. Most are not intended for heavy fighting; their normal use is for reconnaissance, command, control, and communications, or for use against lightly armed insurgents or rioters. Only some are intended to enter close combat, often accompanying convoys to protect soft-skinned vehicles.
Light armored cars, such as the British Ferret are armed with just a machine gun. Heavier vehicles are armed with autocannon or a small, tank gun. The heaviest armoured cars, such such as the German, World War 2 era SdKfz 234 or the modern, US M1128 Mobile Gun System mount the same guns that arm medium tanks.
Vehicle built by railway shop workers for the Danish resistance movement, near the end of World War 2
Armored cars are popular for peacekeeping or internal security duties. Their appearance is less confrontational and threatening than tanks, and their size and maneuverability is more compatible with tight urban spaces designed for wheeled vehicles. They can also be much more easily air-deployed in cargo planes.
Many modern forces now have their dedicated armored car designs, to exploit the advantages noted above. Examples would be the M1117 Armored Security Vehicle of the USA or Alvis Saladin of the post-World War II era in the United Kingdom.
Alternatively, civilian vehicles may be modified into improvised armored cars in ad-hoc fashion. Many militias and irregular forces adapt civilian vehicles into AFVs (armored fighting vehicles) and troop carriers, and in some regional conflicts these "technicals" are the only combat vehicles present. On occasion, even the soldiers of national militaries are forced to adapt their civilian-type vehicles for combat use, often using improvised armor and scrounged weapons.