In the late 19th century, electric cables in New York City transmitted electricity using direct current, a system patented by the Edison company.
This method was expensive and inefficient, resulting in large energy losses along the route and the need for more cables.
The situation changed with the invention of Nikola Tesla, who developed the transmission of electricity using alternating current. This new system was more economical and efficient, and is the method we still use to transmit electricity today.
You can see it on the poles and transformers near your home!