Pharmacology: The study of drugs and their effects on the body - it's like understanding how each tool in your toolbox works.
Pathology: The study of disease causes, processes, development, and consequences - it's like knowing what problems each tool in your toolbox can fix.
Epidemiology: The study and analysis of the distribution patterns and determinants of health and disease conditions - it's like studying why certain tools are needed more frequently than others in different areas or populations.