High-redshift dusty galaxies are excellent sites to investigate mass assembly and growth, total star formation rates (both obscured and unobscured star formation), chemical evolution, and physical conditions. I will talk about two populations of high-redshift dusty galaxies, submillimeter galaxies and quasar 2175 Å dust absorbers, which are selected by their dust emission and dust absorption, respectively. First, I will talk about the physical properties (e.g. stellar masses, SFRs etc.) of gravitationally lensed, dusty, star-forming galaxies (DSFGs) selected by the South Pole Telescope survey. Then I will present a large Spitzer follow-up program of 300 Herschel-selected ultrared (SPIRE S500 > S350 > S250) DSFGs at z ~3-6, and compare with the more numerous z ~ 2 DSFG population. Next I will talk about dusty galaxies in absorption. Quasar 2175 Å dust absorbers (2DAs) are excellent probes of gas and dust properties, chemical evolution and physical conditions in the absorbing galaxies. Keck, MMT, and VLT spectroscopy shows that these 2DAs tag ISM gas with metallicity and dust depletion levels comparable to our own Galaxy. They are expected to be more massive than Damped Lyman-alpha (DLA) galaxies based on the mass-metallicity relation. Using HST direct imaging and grism spectroscopy, we have identified the host galaxy of a 2DA at high redshift for the first time. Synergies between absorption and emission selected galaxies will allow us to achieve a more complete picture of the gaseous, stellar, metal, and dust content in galaxy formation and evolution.