SIMBAD references

In this review/tutorial we explore planetary nebulae as a stage in the evolution of low-to-intermediate-mass stars, as major contributors to the mass and chemical enrichment of the interstellar medium, and as astrophysical laboratories. We discuss many observed properties of planetary nebulae, placing particular emphasis on element abundance determinations and comparisons with theoretical predictions. Dust and molecules associated with planetary nebulae are considered as well. We then examine distances, binarity, and planetary nebula morphology and evolution. We end with mention of some of the advances that will be enabled by future observing capabilities.