What is the difference between pacific islander and asians?

Many of the differences are cultural. They just lead different ways of life. There is no one Asian way of life and no one Pacific Islander way of life. There are some differences in physical characteristics, too, but there are physical differences between different mainland Asian populations as well as between Pacific Islander populations. For example, while most Pacific Islanders look similar to people from the Asian mainland, the indigenous people of Papau New Guinea and Australia look more similar to Africans than anybody else. To sum it up there are so many different people in Asia that you cannot claim that there is one specific thing that makes them different because there are many things. The only real thing that makes Pacific Islanders different from Asians is that they are from the Islands and Asians are from the mainland, but even this doesn't really hold up because most people would consider Japanese people to be Asian, not Pacific Islander, despite being from an island in the Pacific.