How does electron's change heat energy and electrical energy into Light energy{photons}?Please Explain clearly and clearly

well ... we can say that a wave is a sort of disturbance in the surroundings , and to create this disturbance one needs energy .

so when electron moves to an inner orbital under the action of attractive nuclear force , its energy is reduced ..... but energy cnnot be lost or gained as stated by principle of conservation of energy ......... so the energy released by the electron in the transition is emmitted out as a wave ... which when comes in the visible region (depending on its wavelength) appears as light.

same holds for heat