What is immigration and migration are differ?

Answer 1

Immigration is the term used by the host nation to describe the method of dealing with individuals coming to live permanently in a foreign country and the paperwork and departments that deal with it.

For instance " Immigration control is used to prevent undesirables such as criminals from entering a country".

Migration (which is usually applied to animals and birds) can be used when a population travels to a destination (generally but not exclusively) with the intention of returning on a regular (seasonal) basis.

For instance "Swallows migrate to Africa during the winter from northern Europe, returning during the mild summers".

Migration can also used to describe movement of species over a long period of time.

For instance "Humans have migrated from Africa over many thousands of years during pre-history".