Urban air mobility (UAM) is defined in a 2018 National Aeronautics and Space Administration (NASA) paper “as safe and efficient air traffic operations in a metropolitan area for manned aircraft and unmanned aircraft systems” (UAS).
Advanced air mobility, also called advanced aerial mobility, refers to the “adoption of electric and hybrid aircraft to urban, suburban and rural operations.”
According to a 2020 paper by the U.S. National Academics of Sciences entitled Advancing Aerial Mobility: A National Blueprint (link in References below), advanced aerial mobility "involves the emergence of transformative and disruptive new airborne technology supporting an ecosystem designed to transport people and things to locations not traditionally served by current modes of air transportation, including both rural and the more challenging and complex urban environments.”