The Local Group, an ensemble of 35 galaxies most of which are dwarf companions of either M31 or the Milky Way, contains galaxies with a wide variety of masses, luminosities, star formation histories, and chemical and kinematic properties. No two galaxies in the Local Group experienced the same star formation history even within the same morphological type. Star formation episodes vary in length and times ranging from continuous star formation with variable star formation rates to gradually declining rates and episodic star formation, accompanied by either gradual chemical enrichment or almost no enrichment at all. Old populations are a common property of all Local Group galaxies studied in detail so far, though not all appear to share a common epoch of the earliest measurable star formation. Spatial variations in ages and abundances are observed in most Local Group galaxies ranging from widely scattered active regions in high-mass galaxies to centrally concentrated younger star formation episodes in low-mass dwarfs. Both galaxy mass and galaxy environment appear to have a major impact on galaxy evolution. Interactions such as ram pressure and tidal stripping seem to influence the evolution of less massive galaxies, contributing to the observed morphological segregation. Rotation curves and stellar velocity dispersions indicate the presence of dark matter in the majority of Local Group galaxies, although alternative explanations cannot be ruled out. The properties of the stellar populations in these galaxies as well as orbital and kinematic information can impose constraints on the nature and ubiquity of dark matter. Owing to faintness, low stellar density and hence low event probability as well as likeliness of self-lensing, Local Group dwarf galaxies other than the Magellanic Clouds are poorly suited for classical microlensing surveys but might become of interest for future large telescopes that routinely monitor a major fraction of the sky on a nightly basis.
Acknowledgments. This work was supported by NASA through grant HF-01108.01-98A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. I gratefully acknowledge support from the organizers who covered my local expenses. Last but not least I like to thank the editors for their patience while this manuscript was finished.