Is it correct to call America a mainland and Africa a part of the world?

The division into parts of the world and continents is done on different grounds. Parts of the World are areas of the Earth that have been known for their historical connection and ethnicity. Since America (South and North) became known to the civilized world at the same time, they are allocated to one part of the world. But America cannot be called a continent entirely, because the mainland is a large part of the land, surrounded by water on all sides. Separately, North and South America are continents. Africa is also part of the world, as well as a separate continent.