From the Document: "Infectious diseases like COVID-19 [coronavirus disease 2019] can spread rapidly from person to person. Social distancing saves lives by slowing disease transmission and reducing the load on the health care system. The scientific research regarding effective social distancing practices continues to evolve. [...] Social distancing, also known as physical distancing, is the practice of maintaining physical distance from others and avoiding large gatherings, with the intent of reducing the rate of transmission of infectious diseases. COVID-19 has brought social distancing practices to the forefront worldwide as a means of controlling local spread of the disease. [...] Practicing social distancing reduces the rate of new infections by limiting person-to-person transmission. This in turn can 'flatten the curve,' by reducing the peak number of patients to levels the health care system can better manage, ultimately saving lives."
Government Accountability Office: https://www.gao.gov/