Asia is called Asia a 'continent of contrasts' because there are so many cultures, religions, languages, government, lifestyles, traditions. In Asia you can find a diversity of landscape (not only relief form but also climate and type of flora and fauna), beginning with the Caspian plain (which is below sea level) , Himalaya( above 8000 m above altitude), a diversity of people which comes to a diversity of religions
, buddhist, muslim, taoist, etc and a diversity of cultures.The term contrast in this case is used for the big contrast that we see in her territory. If we see the physic map of Asia we see how alternate is her territory, where big and huge mountains are followed by deep valley rivers and fields, so her territory isn't uniform, we don't see large fields without any mountain in it or hills. If we compare her territory with the territory of North America we see the difference in the contest of the word uniform cause the land of north america is very regular , a large plate in the middle and a large field in the east, great mounties in west cordilieres, instead Asia has "up and down" shape of any kind and very different from each other.
Instead the word diversity is used for the diversity of the population of Asia. In Asia there are three kind of human races : the European human race which live in her north, Mongoloid race which is spread in her east and south-east, and Indian race which is in her south and south-west, but these separation isn't very specific,cause the cultures languages and lives of the people in Asia change from one place to another,one example in India we have 4 types of religion : Hinduism, Buddhism, Islamism and Bahawi so this example is enough to demonstrate how large is the diversity of the people and their culture in Asia,