Sometimes people will come to another country because they feel that it is not safe or possible for them to stay in their own country, perhaps because of war or extreme poverty. Under a 1951 UN agreement, these people can seek asylum in the country they arrive in. When someone has asked another country for help in this way, they become an asylum seeker.
The relevant agency in that country will then investigate this person’s circumstances to see if it is appropriate for that person to continue living in their home country. In the UK, this work is done by the Home Office. If the Home Office decides that it is not safe for someone to return to their own country, that person will become a refugee.