Smoke is generated when fire interacts with certain materials, and it consists of tiny particles, gases, and water vapor. Several properties of fire contribute to the production of smoke:

Combustion: Fire is a chemical reaction known as combustion, which occurs when fuel combines with oxygen in the presence of heat. During combustion, the fuel undergoes chemical changes, breaking down into simpler molecules and releasing energy. Incomplete combustion, where the oxygen supply is limited, can lead to the production of smoke.
Pyrolysis: Pyrolysis is the process in which organic materials, such as wood, paper, or plastics, decompose and release volatile compounds when exposed to heat. These volatile compounds, including tars, resins, and other organic substances, can vaporize and form smoke when heated.
Particulate Matter: Smoke contains solid particles, known as particulate matter, which are small bits of incompletely burned or unburned fuel and other materials. These particles are suspended in the hot gases produced by the fire. The composition and size of the particulate matter vary depending on the type of fuel and the temperature of the fire.
Gases and Vapors: Along with particulate matter, smoke also consists of gases and vapors released during combustion. These gases can include carbon monoxide (CO), carbon dioxide (CO2), water vapor (H2O), nitrogen oxides (NOx), sulfur dioxide (SO2), and various volatile organic compounds (VOCs). The specific gases present in smoke depend on the composition of the fuel and the conditions of combustion.
Heat: Smoke is often accompanied by high temperatures due to the intense energy release during combustion. The heat generated by the fire can cause nearby materials to break down and release volatile compounds, contributing to the production of smoke.

It's important to note that smoke can be hazardous, as it contains toxic gases and particles that can be harmful when inhaled. In addition to the potential for respiratory issues, smoke can obscure visibility and contribute to the spread of fires. Proper ventilation and effective fire prevention and control measures are crucial to minimize the production and effects of smoke.