Reconnaissance is a mission to obtain information by visual observation or other detection methods, about the activities and resources of an enemy or potential enemy, or about the meteorologic, hydrographic, or geographic characteristics of a particular area.
Reconnaissance (US Army FM 7-92; Chap. 4)
In military operations, reconnaissance or scouting is the exploration outside an area occupied by friendly forces to gain information about natural features and other activities in the area.
Traditionally, reconnaissance was a role that was adopted by the cavalry. Speed was key in these maneuvers, thus infantry was ill-suited to the task. From horses to vehicles, for warriors throughout history, commanders procured their ability to have speed and mobility, to mount and dismount, during maneuver warfare. Military commanders favored specialized small units for speed and mobility, to gain valuable information about the terrain and enemy before sending the main (or majority) troops into the area, screening, covering force, pursuit and exploitation roles. Skirmishing is a traditional skill of reconnaissance, as well as harassment of the enemy.