Land warfare is categorized by the use of large numbers of combat personnel employing a diverse set of combat skills, methods and a wide variety of weapon systems and equipment, conducted in diverse terrains and weather environments. Land warfare, by the virtue of being conducted in defence of urban and rural population areas, dominates the study of war, and is a focus for most national defence policy planning and financial considerations.
Land warfare in history has undergone several distinct transitions in conduct from large concentration of largely untrained and irregularly armed populace used in frontal assaults to current employment of combined arms concepts with highly trained regular troops using a wide variety of organisational, weapon and information systems, and employing a variety of strategic, operational and tactical doctrines.
Although the land combat in the past was conducted by the Combat Arms of the armed forces, since the Second World War it has largely involved three distinct types of combat units: Infantry, Armour and Artillery. These arms, since the Age of Sail, have used amphibious warfare concepts and methods to project power from the seas and oceans, and since the wide introduction of military transport aircraft and helicopters have used airborne forces and vertical envelopment to the variety of doctrines used to prosecute warfare on land.
Infantry are soldiers who fight primarily on foot with small arms in organized military units, though they may be transported to the battlefield by horses, ships, automobiles, skis, cargo planes, or other means.
Combat vehicles provide the means to mobilize heavy firepower to engage opposing forces including other combat vehicles. Combat vehicles are usually equipped for driving in rugged terrain. They are usually protected against other common threats with armor and other countermeasures.