Grids are nearly always synchronous, meaning all distribution areas operate with frequencies synchronized (so that voltage swings occur at almost the same time). This allows transmission of AC power throughout the area, connecting a large number of electricity generators and consumers and potentially enabling more efficient electricity markets and redundant generation.

The combined transmission and distribution network is part of electricity delivery, known as the "power grid" in North America, or just "the grid." In the United Kingdom, India, Tanzania, Myanmar, Malaysia and New Zealand, the network is known as the National Grid.

Although electrical grids are widespread, as of 2016, 1.4 billion people worldwide were not connected to an electricity grid.As electrification increases, the number of people with access to grid electricity is growing. About 840 million people (mostly in Africa) had no access to grid electricity in 2017, down from 1.2 billion in 2010.

Source:

https://en.wikipedia.org/wiki/Electrical_grid