Armoured personnel carrier

An APC is either wheeled or tracked, or occasionally a combination of the two, as in a half-track.

Wheeled vehicles are typically faster on road and less expensive, however have higher ground pressure which decreases mobility offroad and makes them more likely to become stuck in soft terrains such as mud, snow or sand.[3]

Tracked vehicles typically have lower ground pressure and more maneuverability off-road. Due to the limited service life of their treads, and the wear they cause on roads, tracked vehicles are typically transported over long distances by rail or trucks.[3]

Many APCs are amphibious, meaning they are able to traverse bodies of water. To move in water they will often have propellers or water jets, or be propelled by their tracks. Preparing the APC to operate amphibiously usually comprises checking the integrity of the hull and folding down a trim vane in front. Water traverse speed varies greatly between vehicles and is much less than ground speed. The maximum swim speed of the M113 is 3.6 mph (5.8 km/h),[4] about 10% its road speed, and the AAVP-7 can swim at 8.2 mph (13.2 km/h).

LVTP-5 amphibious armoured fighting vehicles, 1966

Armoured personnel carriers are typically designed to protect against small arms and artillery fire. Some designs have more protection; the Israeli IDF Namer has as much armour as Merkava main battle tank. Armour is usually composed of steel or aluminium. They will also use bulletproof glass.

Many APCs are equipped with CBRN protection, which is intended to provide protection from weapons of mass destruction like poison gas and radioactive/nuclear weapons.

Generally APCs will be lighter and less armoured than tanks or IFVs, often being open topped and featuring doors and windows, as seen in the French VAB.

Armoured personnel carriers are designed primarily for transport and are lightly armed. They may be unarmed, or armed with some combination of light, medium, heavy machine guns, or automatic grenade launchers.

In Western nations, APCs are frequently armed with the .50 calibre M2 Browning machine gun, 7.62mm FN MAG, or 40mm Mk 19 grenade launcher. In former Eastern bloc nations, the KPV, PKT and NSV machine guns are common options.

In "open top" mounts the gunner sticks out of the vehicle and operates a gun on a pintle or ring mount. A ring mount allows the gun to traverse 360 degrees, a pintle mount has a limited field of fire. It can be preferable to an enclosed gunner because it allows a greater field of view and communication using shouts and hand signals. However, the gunner is poorly protected and at risk of injury in the event of vehicle rollover. During the Vietnam War, M113 gunners often suffered heavy casualties.

Enclosed vehicles are equipped with turrets that allow the crew to operate the weapons system while protected by the vehicle's armour. The Soviet BTR-60 has an enclosed turret mounted with a KPV heavy machine gun with a PKT coaxial machine gun. The U.S. Assault Amphibious Vehicle, Personnel (AAVP7's) machine guns (an M2, .50 caliber MG and a Mk 19 grenade launcher) are in fully enclosed turrets (turrets typically have optics which make them more accurate).

More recently, APCs have been equipped remote weapon systems. The baseline Stryker carries an M2 on a Protector remote weapons system.

wheeled IFV

The infantry fighting vehicle (IFV) is a derivative of the APC. Various classes of infantry fighting vehicles may be deployed alongside tanks and APCs, in armoured and mechanized forces. The fundamental difference between an APC and IFV, is the role they are designed to serve. The CFE treaty stipulates an infantry fighting vehicle is an APC with a cannon in excess of 20 mm, and with this additional firepower the vehicle is more involved in combat, providing fire support to dismounted infantry.

The Bundeswehr ATF Dingo (on a Unimog chassis) is an IMV used by several European armed forces

"Infantry mobility vehicle" (IMV) is a new name for the old concept of an armoured car, with an emphasis on mine resistance. They are primarily used to protect passengers in unconventional theatres of war.

The South African Casspir was first built in the late 1970s. In the 21st century, they gained favour in the post-Cold-War geopolitical climate. Identical to earlier High Mobility Multipurpose Wheeled Vehicle (HMMWV) in design and function, the uparmoured M1114 HMMWV is a clear example of this. The addition of armour provides protection to passengers. M1114s have been largely replaced by purpose-built Mine Resistant Ambush Protected (MRAP) vehicles.

IMVs generally feature a v-shaped underbelly designed to deflect mine blasts outwards, with additional crew protection features such as four-point seat belts, and seats suspended from the roof or sides of the vehicle. Many feature a remote weapon system. Usually four-wheel drive, these IMVs are distinct from 8-, 6-, and 4-wheeled APCs (such as the VAB), being closer in appearance to civilian armoured money transporters.