Biofields integrate several physiological levels temporally and spatially. Physiological coherence complements metabolic processes, which preserve animal cellular and physiological function. Coherent physiology involves internal biological system coordination and sensitivity to specific stimuli and signal frequencies. Current research shows that exogenous biologically and non-biologically generated energy entrains human physiological systems. Electrical and magnetic field measurements during physiological activity may occur from metabolic processes or unknown physiological actions. All living things resonate at similar or coherent frequencies; therefore, species will eventually share resonance. Resonance is a term closely related to awareness, interregional connections or disconnection in the brain, and the integratory function of the brain. It can describe synchrony, vibration, or harmony more broadly. The synchronized electrical cycles of the brain have similar resonance patterns. Resonance's significance in fostering integrated brain activity, awareness, awakeness and death are reviewed.