This paper deals with the fundamental aspect of dielectric relaxations in conducting inorganic solids. It has been shown that it is possible to evidence dielectric relaxations due to charge carriers such as electrons (small-polarons) and ions, dipole reorientations (e.g. water molecules in hydrates) and to interfacial polarization phenomena (e.g. grain boundaries) in polycrystalline compounds. The importance of all these phenomena is discussed in relation to their possible interventions in dielectric spectra.