In the electricity sector, distribution refers to the final stage of delivering power from high-voltage transmission lines to individual homes, businesses, and institutions. Distribution systems step down voltage from transmission levels (hundreds of thousands of volts) to usable levels (typically 120/240 volts for residential customers) through substations and transformers. The distribution network includes poles, wires, underground cables, and switching equipment that bring electricity the "last mile" to customers. In most of Canada, local distribution companies (often municipally owned) operate these systems, while separate entities handle generation and transmission. Distribution costs form a significant portion of electricity bills. Modern distribution systems are evolving toward "smart grids" that accommodate solar panels, electric vehicles, and two-way power flows from homes generating their own electricity.