One of the more challenging research areas in cognitive science is the attempt to understand how the brain supports consciousness. This historically philosophical endeavor is now actively studied in the sciences, with research on visual attention being an especially promising area that can further our understanding of consciousness. A major problem with this cross-disciplinary pursuit, however, is that for philosophers and scientists, the terms consciousness, attention, and conscious attention are ambiguous and used differently even by those within the same academic discipline. The goal of this paper is to begin laying the groundwork for a unified study of consciousness by delineating common terminology for attention and consciousness and by identifying the relationship between the two within the study of conscious attention. This includes categorizing current theories according to a spectrum of theoretical complexity.