Combustion is a multidisciplinary phenomenon often involving complicated chemical, physical, mathematical, environmental, economical, and social factors. It is by far the largest means of the energy conversion, and well in excess of 90% of the world's energy needs are satisfied by devices and processes employing some combustion regime. Examples of combustion range from an open campfire somewhere in a remote tropical jungle to the intense flames in Voulcain rocket engine of the Ariane‐5 launcher consuming several hundreds of kilograms of hydrogen and oxygen every second. Despite the large variety in its manifestations, combustion involves relatively few physical factors; more often than not, it is the physical aspects of combustion that determine the feasibility of a given energy conversion device. The aim of this chapter is to provide some basic information and guidance where further information may be found about physics of combustion.