Immigration detention is the policy of holding individuals suspected of visa violations, illegal entry

Illegal entry

Illegal entry is the act of foreign nationals arriving in or crossing the borders into a country in violation of its immigration law.Migrants from nations that do not have automatic visa agreements, or who would not otherwise qualify for a visa, often cross the borders illegally in some areas like...

 or unauthorised arrival

Unauthorised arrival

An unauthorised arrival is a person who has arrived in a country when they are not a citizen of that country and does not have a valid visa or does not satisfy other required conditions for entry to that country....

, and those subject to deportation and removal in detention

Detention (imprisonment)

Detention is the process when a state, government or citizen lawfully holds a person by removing their freedom of liberty at that time. This can be due to criminal charges being raised against the individual as part of a prosecution or to protect a person or property...

 until a decision is made by immigration

Immigration

Immigration is the act of foreigners passing or coming into a country for the purpose of permanent residence...

 authorities to grant a visa

Visa (document)

A visa is a document showing that a person is authorized to enter the territory for which it was issued, subject to permission of an immigration official at the time of actual entry. The authorization may be a document, but more commonly it is a stamp endorsed in the applicant's passport...

 and release them into the community, or to repatriate

Repatriation

Repatriation is the process of returning a person back to one's place of origin or citizenship. This includes the process of returning refugees or soldiers to their place of origin following a war...

 them to their country of departure. Mandatory detention is the practice of compulsorily detaining or imprisoning

Prison

A prison is a place in which people are physically confined and, usually, deprived of a range of personal freedoms. Imprisonment or incarceration is a legal penalty that may be imposed by the state for the commission of a crime...

 people seeking political asylum, or who are considered to be illegal immigrants

Illegal immigration

Illegal immigration is the migration into a nation in violation of the immigration laws of that jurisdiction. Illegal immigration raises many political, economical and social issues and has become a source of major controversy in developed countries and the more successful developing countries.In...

 or unauthorised arrival

Unauthorised arrival

An unauthorised arrival is a person who has arrived in a country when they are not a citizen of that country and does not have a valid visa or does not satisfy other required conditions for entry to that country....

s into a country.
Several Asian nations are known to imprison immigrants on visa violations or for alleged trafficking

Human trafficking

Human trafficking is the illegal trade of human beings for the purposes of reproductive slavery, commercial sexual exploitation, forced labor, or a modern-day form of slavery...

, including the victims of trafficking and smuggling

Smuggling

Smuggling is the clandestine transportation of goods or persons, such as out of a building, into a prison, or across an international border, in violation of applicable laws or other regulations.There are various motivations to smuggle...

.