Psychology is the scientific study of human behavior and cognitive processes. It is derived from two separate fields, Philosophy and Physiology. It consists of processes like attention, memory, perception, learning etc.. 

Cognitive psychology is the scientific study of mind and mental function, including learning, memory, attention, perception, reasoning, language, conceptual development, and decision making. The modern study of cognition rests on the premise that the brain can be understood as a complex computing system.

Human physiology is the science of the mechanical, physical, and biochemical functions of normal humans or human tissues or organs. The principal level of focus of physiology is at the level of organs and systems.