Inertial mass in the context of "Net force"

Historically, cavalry (from the French word cavalerie, itself derived from cheval meaning "horse") are groups of soldiers or warriors who fight mounted on horseback. Until the 20th century, cavalry were the most mobile of the combat arms, operating as light cavalry in the roles of reconnaissance, screening, and skirmishing, or as heavy cavalry for decisive economy of force and shock attacks. An individual soldier in the cavalry is known by a number of designations depending on era and tactics, such as a cavalryman, horseman, trooper, cataphract, knight, drabant, hussar, uhlan, mamluk, cuirassier, lancer, dragoon, samurai or horse archer. The designation of cavalry was not usually given to any military forces that used other animals or platforms for mounts, such as chariots, camels or elephants. Infantry who moved on horseback, but dismounted to fight on foot, were known in the early 17th to the early 18th century as dragoons, a class of mounted infantry which in most armies later evolved into standard cavalry while retaining their historic designation.

Cavalry had the advantage of improved mobility, and a soldier fighting from horseback also had the advantages of greater height, speed, and inertial mass over an opponent on foot. Another element of horse mounted warfare is the psychological impact a mounted soldier can inflict on an opponent.