Here are names and terms often used in the debate over MRAPs and Humvees:
Buffalo -- A larger, mine-clearing MRAP made by Force Protection Inc. of South Carolina.
Bushmaster -- Australian MRAP vehicle made in cooperation with Oshkosh Truck Co.
Central Command (CENTCOM) -- The joint military command based in Tampa, Fla., that oversees forces in Iraq and Afghanistan. Headed by a four-star officer.
Cougar -- A mine-resistant ambush-protected vehicle made by Force Protection Inc.
EFP -- Explosively formed projectile, a homemade bomb that creates a metal projectile that punches through a vehicle's armor.
EOD -- Explosive ordnance disposal, the process of detecting and dismantling bombs, artillery shells and mines.
Forces Command (FORSCOM) -- An Atlanta-based Army command responsible for training, mobilizing and deploying soldiers throughout the world.
Force Protection Inc. -- One of the major U.S. makers of MRAP vehicles. Based in Ladson, S.C., it landed the contracts to build Buffalo and Cougar MRAPs.
House Armed Services Committee -- The House panel that helps determine overall military policy.
Humvee -- Officially known as the High Mobility Multipurpose Wheeled Vehicle (HMMWV), this is the military's main workhorse.
IED -- Improvised explosive device. This refers to most homemade bombs used by Iraqi insurgents.
JERRV -- Joint Explosive Ordnance Disposal Rapid Response Vehicle, which is a larger version of the Cougar made specifically for units that dispose of explosives.
JIEDDO -- Joint IED Defeat Organization, the Pentagon agency responsible for developing ways to fight improvised explosive devices.
Joint Chiefs of Staff -- The top officers of the four main branches of the military. They shape overall military policy, report to the secretary of defense and advise the president.
MaxxPro -- A Category I MRAP made by Warrenville, Ill.-based International Military and Government, one of the main Pentagon MRAP contractors.
M-1114 -- The main version of the up-armored Humvee.
MRAP -- Mine-resistant ambush-protected vehicle. Made with a V-shaped, monococque hull, the MRAP is built to disperse the force of an explosion from below the vehicle.
Operational needs statement -- The Army's term for requests from field commanders for commercially available equipment to aid combat troops.
Rapid Acquisition Authority -- The Pentagon's ability to tap into special funds to rush needed equipment to the field. Congress has criticized the Pentagon for not using the authority enough.
Research, Development & Engineering Command (RDECOM) -- Army command that develops new equipment for troops in the field.
RG-31 -- The MRAP vehicle made by BAE Systems and developed in South Africa.
Tank-Automotive and Armaments Command (TACOM) -- The Army's main command responsible for military vehicles.
Urgent needs request -- A request from Marine commanders in the field for commercially available equipment that can help combat forces. All such requests are reviewed by the service's headquarters and by an overall Pentagon committee before they are rejected or approved. Different services use slightly different terms to refer to these requests.