Parsi: They are called «Parsi» because they came from Persia. They live in Pakistan, Bombei, India (were chased by the muslims). They folow the Zoroastrianism religion. They are different from Iranis. A tradition says that when you die the other Parsis have to take out of you all your purity trought the pollution.
Diaspora: The dispersion of people of the same religion to another places to live.