What does emigration mean? In what way it affects the country from where the migrants come?

It means leaving one's resident country with the intention to settle down elsewhere. It is especially migration from one's native country.

Emigration has advantages as well as disadvantages:

Advantages

1. Remittances
2. Better job opportunities for locals
3. Knowledge and skill flow

Disadvantages

1. Loss of skilled labour
2. Fall in demand of home goods
3. Social impact