A migrant worker is someone who regularly works away from home, if they even have a home.
Although the United Nations' use of this term overlaps with 'foreign worker', the use of the term within the United States is more specific. In the United States, the term is most commonly used to describe low-wage workers performing manual labor in the agriculture field.
Migrant workers are often forced into poor situations and can be expelled if they do not have a legal permit to stay, but are supported by the International Labour Organization. In 1990, the United Nations also adopted the Convention on the Rights of All Migrant Workers to protect them.