There are various absorption lines that correspond to the difference in energy levels between electron orbits. E.g. the https://en.wikipedia.org/wiki/Lyman-alpha_line correpsonding to the difference in energy between an electron orbiting a hydrogen atom in its ground state and the $n=2$ orbital.
But how "wide" are these lines? How large is the range of values that can cause a hydrogen atom to absorb these photons and excite the electron. And what happens to the energy above the bare minimum required?
Similarly, how wide are the emission lines?