Diversity is the term that applies to dissimilarities. It may be in language, food, culture, living, religion, etc. India is a unique country where one can observe it extensively. There are a number of festivals, languages, dresses, religions, etc. in India. Still people of India are Indians and they salute the one flag and sing one national anthem. It is unity in diversity.
Diversity occurs when we travel to different parts of the world. Since time immemorial people have been visiting different lands in order to learn something and for trade. They adopted different styles, languages and cultures from all those places.
Diversity also occurs due to geographical variations and natural calamities. For example, Kashmir is a cold place and temperature goes even below 00C. Naturally Kashmiri people wear woolen clothes, eat and drink hot food. On the other hand, people in desert areas use different clothes because it is veiy hot there.