However, infantry riding on top of tanks had no kind of protection. The number of casualties was very high. There was clearly the need for a tracked vehicle which could carry troops to the battle zone, keep pace with main battle tanks (MBTs) and which offered some protection against enemy fire. The vehicle had to have good cross country mobility and an amphibious capability in order to keep up with the MBTs. Hence the concept of the Armoured Personnel Carrier and Infantry Fighting Vehicle was born.

In line with this revolutionary concept the Red Army developed the Boyevaya Mashina Pekhoty 1 (BMP 1) IVF in the early 1960s. It was a tracked vehicle with a crew of three men and could carry eight infantrymen. It was armed with a 73 mm main gun, a 7.62 co-axial machine gun and carried a "Sagger" anti-tank guided missile. When the BMP reached the battlefield the infantry inside could either dismount the vehicle and fight on foot or fight from inside the vehicle. The BMP has firing ports and vision devices for the soldiers inside and has full Nuclear/Biological/Chemical (NBC) protection for the crew and infantrymen. The latest version of this mass-produced and widely-exported revolutionary design is the BMP - 3 which is more heavily armed and armoured than its predecessors.

The APC is normally designed to transport the infantry as close to their military objective as possible where they can then dismount and fight on foot. The British Army's Warrior is a good example of such a vehicle. On the other hand, the IVF is designed to play an offensive role on the battlefield with the infantry firing from within the vehicle. A good example of a modern IFV is the American Army's Bradley. The IFV is usually more heavily armed and armoured than the APC. The British Warrior's main armament is a 30 mm cannon whereas the American Bradley is armed with a 25 mm cannon and carries 2 anti-tank guided missiles. Most APCs and IFVs are tracked but some are wheeled vehicles like the French Army's Panhard VCR or the Swiss Army's MOWAG Piranha. Wheeled APCs tend to be easier and cheaper to operate and maintain and have greater strategic mobility than their tracked counterparts. However, tracked APCs and IFVs tend to have better levels of armour protection and superior cross-country mobility. This means they have greater chances of survival on the battlefield.

Most APCs and IFVs have all-welded steel or aluminium hulls which provide those inside with protection from shell splinters and small arms fire. Combat experience in the Middle East has made the armed forces of some nations provide their APCs with additional armour packages to increase their battlefield survivability. Armed forces involved in UN Peacekeeping missions in various parts of the world also tend to increase the levels of armour protection for their APCs. The US Army has installed Explosive Reactive Armour (ERA) on many of its Bradley IFVs. ERA offers greater protection for those inside than the conventional "passive" armour fitted to most APCs and IVFs.