What are the categories of consciousness and what is an assessment?

Assessment: AVPU (alert, verbal, pain, unresponsive) Alert (responds immediately), Confused (disoriented to time or place), Delirious (disoriented to time, place, and person), Lethargic (state of drowsiness), Obtunded (displays dull indifference to external stimuli), Stuporous (aroused only by vigorous and continuous external stimuli), Comatose (Vigorous stimulation fails)