The main difference lies in their purpose and the voltage they carry. transmission lines move large quantities of power over long distances from generating stations to substations, operating at very high voltages (typically 110 kV and above). Distribution lines, on the other hand, take power from substations and deliver it to end-users over shorter distances at much lower, medium, and low voltages. Think of it like a highway system: transmission lines are the interstate highways, and distribution lines are the local roads that take you to your final destination.