Take it one level lower on down, when you're the size of an electron, orbitals are wild, turbulent places, sometimes sharing electrons which also often get zapped by light, so they jump to a higher orbital, then they randomly spit out that photon and reappear back down... all the orbitals of a molecule violently jiggling all the time.

Take photosynthesis. Simply put and to oversimplify but it's essentially accurate, a photon hits an electron bullseye in a leaf molecule, which sets off a wave of energy in motion, breaking up molecules, reassembling them into sugars and waste product (oxygen).
A red photon raises an electron one orbital up, that sets off one process at a certain level of energy. A blue photon raises an electron two orbitals up, that sets off another process at twice the energy level.