Contact tracing is a public health strategy used to identify and notify individuals who may have been exposed to a contagious disease, such as COVID-19. When a person tests positive, health officials gather information about their recent interactions and locations to determine who might be at risk of infection. Once potential contacts are identified, they are informed about their exposure and advised to monitor for symptoms or get tested. This process helps to slow the spread of the disease by ensuring that those who may be infected take appropriate precautions, such as self-isolation or seeking medical care.