An army (from Latin armata "armed (things)" via Old French armée, "armed" (feminine), in the broadest sense, is the land-based Military of a nation. It may also include other branches of the military such as the air force via means of aviation corps. Within a national military force, the word Army may also mean a field army, which is an operational formation, usually made up of one or more corps.
A standing army is an army composed of full-time career soldiers who 'stand over', in other words, who do not disband during times of peace. They differ from army reserves who are activated only during such times as war or natural disasters.
In several countries the army is officially called the land army to differentiate it from an air force called the air army, notably France. In such countries, the word "army" on its own retains its connotation of a land force in common usage. The current largest army in the world by number of active troops is the People's Liberation Army of China with 2,250,000 active troops and 800,000 reserve personnel.
By definition, irregular military is understood in contrast to regular armies which grew slowly from personal bodyguards or elite militia.
Aimpoint's well-known CompM2 and ML2 red dot sights are meant for small calibre weapons. CompM2 (M68) is NVD compatible and is the official red dot sight of the US Army.Source: www.army-technology.com