Planetary nebulae are the spectacular products of low- and intermediate-mass stellar evolution. Understanding their formation and origin is key to understanding fundamental yet highly uncertain physics of single and binary star evolution. The shapes and spectral characteristics of PNe are unique and visible out to great distance. For a long time, the use of PNe as effective probes of stellar populations and galactic dynamics has been very successful. The current symposium is a continuation of a 5year cycle of PN IAU Symposia proposed and organized by the IAU PN WG, based on a continuing stream of interest for this fascinating subject, with connections to stellar evolution, gas and dust chemistry and recycling, stellar population in the Milky Way, in the Local group, and in external galaxies as well.