The Leave to Remain is the legal status of a person issued by a government office of internal affairs to one who is not yet a citizen. In most stable countries, Indefinite leave to remain

Indefinite leave to remain

Indefinite leave to remain is an immigration status granted to a person who does not hold right of abode in the United Kingdom , but who has been admitted to the UK without any time limit on his or her stay and who is free to take up employment or study, without restriction...

 (as is known in the UK) is granted to these foreign citizens after a specified period spent within its borders. This is usually the final step towards naturalization

Naturalization

Naturalization is the acquisition of citizenship and nationality by somebody who was not a citizen of that country at the time of birth....

 which in turn leads to full citizenship

Citizenship

Citizenship is the state of being a citizen of a particular social, political, national, or human resource community. Citizenship status, under social contract theory, carries with it both rights and responsibilities...

.

A Leave to Remain need not be indefinite.

Compare to Permanent Resident status in the United States and Permanent Resident status (formerly classified as Landed Immigrant status) in Canada.