Publisher Summary This chapter focuses on the concept of Stark broadening. The meaning of Stark broadening has developed from the original concept of statistically distributed Stark shifts due to electric fields produced by charged particles to the general notion of all effects on spectral lineshapes caused by perturbing electrons and ions, inclusive of collective interactions. As a rule, charged particle effects dominate over those caused by electrically neutral perturbers as soon as the radiating or absorbing gas is, say, 1% ionized. Because in such situations molecules are relatively rare, practically all Stark broadening research has centered on atoms or ions as radiating or absorbing systems immersed in plasma. Turbulent Stark shifts apply equally well if both growing and decaying plasma waves interact with the atom. However, as in the hydrogen case, the dissipative part of the lineshape operator is severely affected and the wave contribution to it may even vanish, depending on amplitudes and growth rates.