Energy is either released or absorbed. When an electron jumps from high energy to lower, a photon is emitted or released. when the electron goes from low to high, energy is absorbed.
In any material there are various energy level in which electrons are filled. Suppose there are two energy level in a material. Lower energy level has 1eV energy it means atoms which have 1eV can stay in this energy level.Other energy level has 3eV energy it means atoms which have 3eV energy can stay in this state. If atom from 3eV energy level jumps into 1eV energy level that time atom has to emit its excess energy (3eV-1eV=2eV) in the form of photon because in 1eV energy level atoms which have 2eV energy can stay.
