Glow discharges are used in a large number of application fields. Their use as a spectroscopic source for analytical chemistry is only one application; they are much more widely used for other purposes, such as in the micro-electronics industry and in materials technology, and also as lasers, various kinds of light sources, and in the new upcoming plasma displays. In this review we will give a brief overview of these applications. In order to improve the results in these application fields and, in general, to obtain a better understanding of the plasma processes, various modeling approaches for glow discharges, mainly for the non-analytical applications, have been described in the literature, of which a brief overview will be given here. Finally, our own modeling network, which is specifically applied to analytical glow discharges, will be briefly described and some typical results will be shown.