Military history is the study of armed conflict in the history of humanity, and its impact on the societies, cultures and economies thereof, as well as the resulting changes to local and international relationships.
Professional historians normally focus on military affairs that had a major impact on the societies involved as well as the aftermath of conflicts, while amateur historians and hobbyists often take a larger interest in the details of battles, equipment, and uniforms in use.
Industrial warfare is a period in the history of warfare ranging roughly from the early 19th century and the start of the Industrial Revolution to the beginning of the Atomic Age, which saw the rise of nation-states, capable of creating and equipping large armies, navies, and air forces, through the process of industrialization.
The era featured mass-conscripted armies, rapid transportation (first on railroads, then by sea and air), telegraph and wireless communications, and the concept of total war. In terms of technology, this era saw the rise of rifled breech-loading infantry weapons capable of high rates of fire, high-velocity breech-loading artillery, chemical weapons, armoured warfare, metal warships, submarines, and aircraft.
The pincer movement, or double envelopment, is a military maneuver in which forces simultaneously attack both flanks (sides) of an enemy formation. This classic maneuver has been important throughout the history of warfare.
The pincer movement typically occurs when opposing forces advance towards the center of an army that responds by moving its outside forces to the enemy's flanks to surround it. At the same time, a second layer of pincers may attack the more distant flanks to keep reinforcements from the target units.