A green card is a document that grants you lawful permanent residence status in the United States. It gives you the right to live here on an ongoing basis. It also gives you the authorization you need to find and keep a job in the U.S.
There are several different categories of green cards. Based on your situation, there are also different processes involved in obtaining them. The process you go through depends partly on whether you are already in the United States or if you wish to come to the U.S. but are currently still in your own country.
Adjustment of status
If you are already present in the United States, you may be able to obtain a green card through an adjustment of status. According to U.S. Citizenship and Immigration Services, this saves you the inconvenience of having to return to your home country to complete the processing of your visa. However, you have to meet the eligibility requirements. Adjustment of status may be available to you if you belong to a certain immigration category, such as an international student or a temporary visitor.
Adjustment of status is only available to those already present in the United States. If you are still in your home country, you may still be able to obtain a green card through a different process. Consular processing is a means by which you might be able to obtain a green card from outside the United States. You must locate a U.S. Consulate or Embassy in your home country. Here you will have an interview after you submit the necessary documentation according to stringent filing requirements. This is a complex process involving strict procedures that you must follow.