Systems biology is introduced as studying biological systems at multiple levels of organization to understand properties that emerge from interactions between components. Experimental methods like genomics, proteomics, and metabolomics are used to generate large data sets, which are then analyzed using mathematical and statistical tools to model biological networks and systems. Systems approaches are shown to have medical applications in identifying diagnostic markers, personalizing therapy, and predicting comorbidities by analyzing whole disease networks. The future of medicine is proposed to involve predictive, preventive, personalized, and participatory approaches based on systems biology insights.