The number of continents varies according to culture and country, and this is due to the definition of "continent". The strictest definition would be that it is a large, continuous and separate land mass surrounded by water. With this strict criterion, there would only be three continents, since Africa, Europe and Asia are joined among themselves, so much that there are those who speak of an "Afro-Eurasia" continent.The definition of continent is not strictly geographic but cultural. These cultural traditions have led that in the education system, the media and even the scientific area of each region of the world, it is taught different number of continents. In some parts of the world it is said that there are five in others six or even seven continents according to each tradition.A clearly example of the above is Europe, in the strict way, it is a great peninsula of Asia even though, it is considered a continent. Africa, even though, it is joined to Asia because of the Suez isthmus, it is considered a continent. In the case of Oceania/Australia the name also varies. English-speaking countries and Australia itself define the continent as Australia. On the other hand, Canada the Latin countries of Europe and Latin America speak of Oceania as they include the islands that are linked to Australia.Until the Second World War, in the United States people learned that there was only one continent called "the Americas", but since then, like other English-speaking countries, they started talking about seven continents, dividing America into two, the North and the South.

Actually, a single global ocean is divided into several oceanic components. Those ones conventionally separate some continents from others.