Well, migration is the act of moving from one place (ie. from one country) to another. Immigration is ''migration in''. The idea is about coming to a country. Emigration is ''migration out'' (Latin prefix 'ex-'; here, you just have 'e-'). The idea is about leaving a country.

Imigration is the process of coming to live permanetly in a country that is not your own; the number of people who do this. We use word "migrate" (verb) about a large number of people who go and live and work in another place. " Migration" is a noun.

Hi, Mahesh Kumar! Immigration - it means I'm going to you in Pakistan. Migration - that means a lot of girls coming to you in Pakistan. हाय, महेश कुमार! आप्रवासन - यह मतलब है कि मैं पाकिस्तान में आप के लिए जा रहा हूँ. प्रवासन - कि पाकिस्तान में आप के लिए आ रहा है लड़कियों की एक बहुत मायने रखती है.