Question

How is the some contenent seprate from the rest of asia

Answer 1

The boundaries between the continents of Earth are generally a matter of geographical convention. Several slightly different conventions are in use. The number of continents is most commonly considered seven but may range as low as four when the Americas and Afro-Eurasia are each considered a single continent. According to the definition of a continent in the strict sense, an island cannot be part of any continent, but by convention and in practice most major islands are associated with a continent.
There are three overland boundaries subject to definition:
between Europe and Asia (dividing Eurasia ): along the
Turkish Straits, the Caucasus and the Urals (historically also north of the Caucasus, along the Kuma–Manych Depression or along the Don River)
between Asia and Africa (dividing Afro-Eurasia into Africa and Eurasia ): at the Isthmus of Suez
between North America and South America (dividing the
Americas): the Isthmus of Panama
While the isthmus between Asia and Africa and that between North and South America are today navigable, via the Suez and Panama canals, respectively, diversions and canals of human origin generally are not accepted on their own accord as continent-defining boundaries; the Suez Canal happens to traverse the isthmus between the Mediterranean Sea and Red Sea , dividing Asia and Africa. The remaining boundaries concern the association of islands and archipelagos with specific continents, notably:
the delineation of Southeast Asia from Australasia
the delineation between Africa, Europe and Asia in the
Mediterranean Sea
the delineation between Asia and Europe in the Arctic Ocean
the delineation between Europe and North America in the
Atlantic Ocean
the delineation between North and South America in the
Caribbean Sea
the delineation of Asia from North America in the North Pacific Ocean
Europe and Africa
The Mediterranean Sea