Far Infrared Emission from Galaxies

The relationship between far infrared sources and star formation is discussed. It is argued that the relationship of star formation to compact nuclear sources and the relative importance of these fundamentally different types of activity in the most luminous galaxies is still unclear. Although there is evidence for a general correlation between far infrared emission and the amount of interstellar matter present, there are also indications of significant deviations from a simple stochastic model.