Which of the following best defines fire?

The correct choice identifies fire as a rapid oxidation process that produces both light and heat. Fire is fundamentally a chemical reaction that occurs when a combustible material reacts with oxygen, generating energy in the form of heat and light. This process is characterized by its speed; a fire spreads quickly due to its dependence on the availability of fuel and oxygen.

The production of heat causes a continued reaction, which can result in flames. The visible phenomena of flames and heat are essential elements of what people commonly recognize as fire. Understanding this definition is crucial for fire protection as it underlines the importance of controlling the elements responsible for fire - heat, fuel, and oxygen - to prevent its spread and ensure safety. This encompasses much of the work done by fire protection professionals.