Battle line

A formation where soldiers move out of marching columns and form into lines of battle or columns of attack for both attack and defense.

Bivouac area

A temporary encampment.

Command post

A site used by a commander to control the operation of his military forces. Also called "headquarters."

Disengagement

When one or both military forces voluntarily withdraws from combat.

Flanking movement

To pass around or turn the right or left of an enemy force.

Observation post

Vantage point used to observe the enemy or a military engagement.

Picket line

A position held by a detached body of soldiers serving to guard an army from surprise.

Reserve area

An area where troops are held back from battle while the commander decides how to use them: to reinforce part of his line; counterattack the enemy; or to serve as a rearguard holding force against a victorious enemy.

Retrograde

The forced withdrawal of troops from an enemy or an advanced position.

Rout

A decisive or disastrous defeat.

Signal station

Vantage point used to transmit information from a forward area to a rear area.

Skirmish line

A small body of troops deployed in advance of a battle line to initiate contact with the enemy.