A settler is a person who has migrated to an area and made a permanent home there. Many times the reason is to colonize the area.
Many times in history settlers live on land which used to belong to people who had lived there a long time. These people are known as indigenous people. Other names are natives, Aborigines or, in the Americas, Indians. This land is usually settled against the wishes of the indigenes. It is then controlled, defended and grown by force.