A resident alien is a foreigner who lives in a country long-term, but has not been accepted as a citizen of that country. The alien is a bona fide foreign resident, in that he or she is in the country through legal means, and usually has the right to work. If the foreigner was not in the country legally, the term applied would most likely be illegal alien or undocumented alien. Resident alien is a more permanent status with more privileges than a non-resident alien, who is just visiting. Nevertheless, such a person often does not have the same rights as citizens, especially when it comes to voting in a democracy.
In most cases except for voting and any military service requirements, the resident alien functions much like any other citizen of the country. If the individual is earning income while in the country, he or she must pay taxes, if the country has an income tax. In some countries, resident aliens may not be able to own real estate, but if they do, they will have to meet any tax obligations on that as well.
A resident alien is different from a non-resident alien in that the individual is likely staying in the country for a longer period of time. Rather than entering a country on a tourist visa, the individual likely has some other type of visa. The most common visas for resident aliens are those related to being a student and work-related visas. In most cases, those in the country on a student visa will not likely be allowed to hold a job unless they apply for a change of status.
Many may choose to remain a resident alien instead of becoming a citizen for a number of different reasons. For example, those who do not plan to remain in the country for the rest of their lives may decide they do not want to apply for citizenship. In some cases, countries may not allow dual citizenship and becoming a citizen of one country could mean giving up citizenship rights in another country.
Once a person has been granted status as a resident alien, he or she is expected to obey all laws. If an individual is convicted of a serious crime, he or she could have the resident status revoked and be deported. If the person was incarcerated for the crime, the deportation would likely happen after the sentence was served. Those deported may never be granted status as a legal resident in a country again, or may never be granted permission to visit the country under any visa.