This review attempts to highlight two fundamental and complementary aspects of the chromospheric phenomenon; viz., global properties of stellar chromospheres and their variation among the stars, and the underlying fine structure that affects or determines these global properties. After an introductory discussion of the gross vertical structure of a stellar chromosphere, attention is given to the chromospheric geometric extent and its dependence on the position of the star in the HR diagram. This includes a critical review of various explanations of the dividing line that separates red giants from Solar-like stars. A subsequent chapter summarizes main features of proposed chromospheric heating mechanisms and discusses the role that magnetic fields play in the transport and dissipation of energy. The onset of stellar chromospheres and the magnitude of nonthermal motions can be probed by the Wilson-Bappu effect and by similar empirical results. The well-known insensitivity of the CaIIK line width to the stellar activity level might be largely due to a collective effect. The final chapter explores the dependence of chromospheric magnetic fine structure on global stellar properties.