National grid is defined as a network of transmission lines, power stations and substations that supply electricity throughout a country. Synonyms for the term national grid include power distribution network, electric power grid, high-voltage electric grid, electrical substation system, electrical transmission grid, electric utility grid and power infrastructure. These synonyms are often used interchangeably in various contexts when referring to the systems that supply and distribute electricity in a country. The national grid is an essential part of the modern infrastructure that enables people to access electricity in their homes, businesses and institutions, enabling them to function efficiently and effectively.