Anchor Point: An advantageous location, usually a barrier to fire spread, from which to start building a fire line. An anchor point is used to reduce the chance of firefighters being flanked by fire.
Burn Out: Setting fire inside a control line to widen it or consume fuel between the edge of the fire and the control line.
Control Line: All built or natural fire barriers and treated fire edge used to control a fire.
Contain a fire: A fuel break around the fire has been completed. This break may include natural barriers or manually and/or mechanically constructed line.
Control a fire: The complete extinguishment of a fire, including spot fires. Fireline has been strengthened so that flare-ups from within the perimeter of the fire will not break through this line.
Extinguished: All hotspots of fire are completely out. Wildfires can smolder for months, which can make it difficult to confidently say that a fire is extinguished.
Crown Fire (Crowning): The movement of fire through the crowns of trees or shrubs more or less independently of the surface fire.
Defensible Space: An area either natural or manmade where material capable of causing a fire to spread has been treated, cleared, reduced, or changed to act as a barrier between an advancing wildland fire and the loss to life, property, or resources. In practice, "defensible space" is defined as an area a minimum of 30 feet around a structure that is cleared of flammable brush or vegetation.
Escaped Fire: A fire which has exceeded or is expected to exceed initial attack capabilities or prescription.
Extreme Fire Behavior: "Extreme" implies a level of fire behavior characteristics that ordinarily precludes methods of direct control action. One of more of the following is usually involved: high rate of spread, prolific crowning and/or spotting, presence of fire whirls, strong convection column. Predictability is difficult because such fires often exercise some degree of influence on their environment and behave erratically, sometimes dangerously.
Hotspot: A particular active part of a fire.
Hotspotting: Reducing or stopping the spread of fire at points of particularly rapid rate of spread or special threat, generally the first step in prompt control, with emphasis on first priorities.
Information from the National Park Service.