Abstract　 　　
　Although planetary nebulae (PNe) have been known for over 200 years, a theoretical understanding of the origin and evolution of these objects only began 30 years ago. Recent observations in the x-ray, ultraviolet, infrared, submm and mm regions show that PNe are active throughout the electromagnetic spectrum and are excellent laboratories for the study of atomic and molecular processes. Observations by the HST have discovered FLIERS, knots, jets, arcs, rings, and point-symmetric structures that are difficult to explain. ISO observations have discovered many inorganic and organic compounds, some of which have been found in presolar grains in the solar system. The detection of extragalactic PNe also allows them to be used as standard candles for extragalactic distance scales, probes of distribution of dark matter, as well as tools to study the dynamic history of galaxy clusters. A modern understanding of PNe is therefore important for the study of the solar ystem, stellar evolution, interstellar medium, galactic structure and evolution as well as cosmology.

Reference：Kwok, S. 2000, Origin and Evolution of Planetary Nebulae, Cambridge University Press

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