The crucial transition point where electricity shifts from long-distance transmission to local distribution is the substation.

Think of the electricity grid as a hierarchical system of roads:

• transmission lines are the high-voltage "superhighways" that carry massive amounts of power over long distances from generation plants.

• Distribution lines are the smaller "local roads" that branch out from the superhighways to deliver power to homes and businesses.

The substation acts as the interchange between these two systems. It is where the voltage is drastically reduced, making the electricity safe and suitable for local use. This process is essential because the extremely high voltage of transmission lines is far too powerful for direct use by residential and commercial consumers.