what is the difference between a storm and a sewer drain?

Storm Drain

The storm sewer is a system designed to carry rainfall runoff and other drainage. It is not designed to carry sewage or accept hazardous wastes. The runoff is carried in underground pipes or open ditches and discharges untreated into local streams, rivers

Sewer Drain

The sanitary sewer is a system of underground pipes that carries sewage from bathrooms, sinks, kitchens, and other plumbing components to a wastewatertreatment plant where it is filtered, treated and discharged.