Observations of hypercompact HII (HCHII) regions are not easily explained by the standard model of HII regions whose dynamics and evolution are dominated by thermal or turbulent pressure, but these observations are simply understood within the contexts of more recent models that include the gravitational attraction of embedded stars. Each of these more recent models, quenched HII regions, gravitationally trapped HCHII regions, photo-evaporating disks, and champagne flows describes one of the several types of structures that are typically seen in HCHII regions. These different theoretical models and the different bserved structures of HCHII regions may be unified by a single model in which a simple accretion flow is subject to ionizing radiation. The differences in structure result from the differences in the magnitudes of the parameters that describe the accretion flow and ionization: the central mass, gas density, angular momentum, and flux of ionizing radiation. This analysis suggests that the HCHII regions and some ultracompact HII (UCHII) regions form a class of HII regions whose structure, dynamics, and evolution are dominated by the gravitational force of the embedded stars and significantly different from all larger HII regions that are pressure dominated.