The words "visa" and "green card" can mean more than one thing, and can even overlap a bit. In order to clear up misconceptions, this article will explore both the legal meanings and the common uses of these words.
A visa is a document prepared by the U.S. Department of State (DOS), and given out by one of its consulates or embassies around the world. The visa gives people the right to present themselves at a U.S. border or port of entry and seek entry.
(Ultimately, the U.S. Customs and Border Protection officer at the border or airport makes the final decision whether to allow someone into the country. Nonetheless, arriving with a visa is a good indication that entry will be permitted.)
Physically, a visa usually appears as a stamp in one's passport. If and when you receive instructions to go to a U.S. consulate to pick up your visa, it means that you will be getting this stamp or an equivalent document that allows you to enter the United States.
There are two kinds of visas: immigrant and nonimmigrant.
An "immigrant visa" allows a person to become a permanent resident immediately upon U.S. entry. Such a person will receive a green card soon thereafter, and can stay in the U.S. for life (unless the person does something to become deportable).
A "nonimmigrant visa" is only temporary. The person will need to leave by the date shown on the I-94 issued by Customs and Border Protection (CBP) at the U.S. border or entry point. That expiration date can be within a matter of months, for example with visitor visas for tourists (B-2) or businesspeople (B-1). Or the visa might not expire for a number of years, as is the case with work visas such as the H-1B or student (F-1 or M-1) or exchange visitor/scholar visas (J-1).
(ALso see How Long Will Your U.S. Visa Allow You to Stay?.)
"Green card" is the slang term for the plastic photo identification card that someone receives soon after approval as a U.S. lawful permanent resident. The green card itself usually arrives by mail after the person either entered the U.S. using an immigrant visa received from a U.S. consulate; or after the person applied for permanent residence from within the United States (adjustment of status) and received a notice of approval from U.S. Citizenship and Immigration Services (USCIS).
The term "green card holder" is often used to to refer to lawful permanent residents as well as lawful conditional residents, though the latter's status expires in two years (as discussed below).
In most cases, nonimmigrant (temporary) visas, such as a B-2 tourist visa, an H-1B temporary specialty worker visa, or an F-1 student visa can be obtained only at an overseas U.S. consulate.
However, someone already in the U.S. legally can apply to U.S. Citizenship and Immigration Services (USCIS) for what's called a "change of status," for example from F-1 to H-1B. Importantly, receiving that approval to be in the U.S. does not mean the person receives an actual "visa."
Remember, a visa is an entry document, which can be issued only by the DOS outside the United States. So if, for example, the H-1B worker who got a change of status leaves the U.S., he or she will have to make a stop at a U.S. consulate to get an actual visa with which to reenter the United States.
Immigrant visas (such as marriage- or employment-based permanent residence) are also obtained at U.S. consulates around the world. But here too, someone already in the U.S. (in most cases, legally) might be able to "adjust status" and get a green card (permanent residence) without departing. You might say that people who adjust status never get a visa; but they do get a "visa number," even if they don't know about it, as described next.
Adding to the confusion, the word visa can be used in situations involving immigrants who are already in the United States and won't need an entry visa.
Only a limited number of green cards are allowed in certain categories every year, and the government tracks these as "visa numbers." Someone in the back offices of the U.S. State Department must allocate a visa number to each immigrant when as they become available in their category.
Therefore, when you read discussions about your "visa eligibility" or "visa availability," they might refer not only to the actual visa that you pick up overseas, but to the broader, theoretical visa number that the DOS will allocate to you.
A permanent resident's green card carries an expiration date, usually of ten years. This is NOT, however, an indication that the person's status expires or must be re-proven at that time. Lawful permanent residence is truly meant to be permanent, unless the person violates the laws and becomes deportable.
However, U.S. authorities want to make sure all permanent residents get a new card regularly, for which one must submit an application on USCIS Form I-90.
There is one type of green card that can expire, however. This is the type held by what's called a lawful conditional resident. It will expire within two years. People who obtain green cards based on new marriages or as investors in category EB-5 receive this two-year conditional residence at first.
Close to that expiration date, the person must submit an application proving that he or she deserves to be converted to lawful permanent, not just lawful conditional residence. (See Why Some Marriage-Based Green Cards Are Conditional.) If that isn't approved, the person loses status and most likely all right to be in the United States.
Green Cards Don't Work for Easy Entry and Exit Like Tourist Visas
Don't expect a green card to work as a frequent travel pass. A common misconception about green cards is that they allow you unlimited travel in and out of the United States without the hassle of reapplying for visas.
The result of this confusion is a common practice by overseas family members of U.S. citizens or residents who want to be able to pop in for impromptu visits. They sometimes apply for green cards.
But if your plan is to maintain your primary home in another country, the U.S. government might eventually figure this out and cancel your green card. The legal term for this is that you abandoned your U.S. residence. (See issues when traveling with a green card.) You might have to start over and apply for another one; provided, of course, that you intend to make the United States your primary and permanent place of residence.
If, for example, you are married to a U.S. citizen or resident but plan to live in your home country for much of your early marriage, or to shuttle back and forth, you might want to wait until you are really ready to settle in the United States to apply for your permanent resident status based on that marriage.