Glass, on a microscopic scale, epitomizes an inhomogeneous system. Being an in-inherently disordered medium, the environment of each ion in a glass is not identical as in a crystal. In addition, because of differences in the bonding to nearest-neighbor ions and, in multicomponent glass compositions, in the types and statistical distribution of more distant neighbor ions, the local fields at individual ion sites vary. This results in site-to-site differences in the energy levels and the radiative and nonradiative transition probabilities of paramagnetic ions in glasses. Broadband-excited optical absorption and emission spectra and excited-state decays consist of a superposition of contributions from individual ions distributed among the entire ensemble of local environments. The spectra exhibit inhomogeneous broadening and the decays do not have a single exponential time dependence.