Here are some basic ins and outs for legal immigration, according to the U.S. Citizenship and Immigration Services and the U.S. State Department. Refugees and individuals seeking political asylum are treated differently from immigrants.

The first step to U.S. citizenship is a legal permanent residence, commonly called a green card.

Nearly every legal pathway to citizenship requires sponsorship, usually by a family member, employer, or school.

The nation of origin also plays a role as some forms of visas are rarer or unavailable in some countries.

For more information, visit: uscis.gov/graphics/services/residency/index.htm

FAMILY SPONSORSHIP

U.S. citizens and permanent residents are able to sponsor family members for immigration.

However, it's a myth that marrying a U.S. citizen means an automatic green card. In every instance, an immigrant needs an adult family member as a sponsor, and proof of the relationship between the sponsor and immigrant. The sponsor must prove he or she is able to provide for the relative at 125 percent above the mandated poverty line.

There's no waiting period for minor children, parents or the spouse of a U.S. citizen age 21 or older. However, for other categories of family sponsorship, the wait can take years or more, maybe decades.

DIVERSITY LOTTERY

The lottery is a random drawing for permanent immigrant visas. Canada and Mexico are among excluded nations. More than 5.9 million people applied during this year's 60-day application period for one of 50,000 visas.

ADJUSTING STATUS

If an adult has lived in the United States illegally for six months to a year and leaves the country, he or she is barred from applying to re-enter the United States for three years. Anyone who's lived here illegally longer than a year is barred for 10 years, unless that person's absence would cause an immediate relative with legal status to suffer severe hardship.

TEMPORARY VISAS

There are a variety of non-immigrant visas, including those for tourists, students and workers. The visas generally have specific requirements and time limits. They don't place a person on a path for permanent residency. However, it is possible for an employer to petition for a temporary immigrant to receive a green card under some circumstances.

SOURCE: U.S. Citizenship and Immigration Services, U.S. Justice Department