In some places, very few children are in a large area. These people usually live far apart. If there are settlements, they are also far apart. In most places of the world, children of a certain age need to go to school. School of the Air is a phrase which describes children being taught using radio, or other technologies. The children do not need to travel, they stay at home. The phrase was first used for a kind of distance learning, which is targeted at chldren going to primary or secondary schools. It was first used in remote areas of Australia, especially the outback. In these areas, people live too far apart, and there are too few school-age children to run a normal school in a village.