Close Quarters Battle (
CQB) or
close quarters combat (
CQC) is a type of fighting in which small units engage the enemy with personal weapons at very short range, even to the point of hand-to-hand combat. In the typical CQB scenario, the attackers try a very fast, violent takeover of a vehicle or structure controlled by the defenders, who usually have no easy way to withdraw. Because enemies, hostages/civilians, and fellow operators can be closely intermingled, CQB demands a rapid assault and a precise application of lethal force. The operators need great proficency with their weapons, but also the ability to make split-second decisions in order to limit friendly casualties.
http://en.wikipedia.org/wiki/CQB