A kettle of stew over a campfire is heated by two methods: radiation, conduction and convection.
In radiation heat energy is transferred in the form of electromagnetic waves through air, thus allowing the fire to heat the kettle containing the soup.
The hot kettle is then heating up the soup by the process of conduction. In conduction heat is directly transferred from the hot body to the cold body.
The soup gets thoroughly heated by the process of convection. In convection the hot liquid particles have high energy and they move rapidly to take the place of particles that have less heat energy. In this way heat gets transferred from the hot to the cold part of the soup.
