The biggest difference between a temporary work visa and a green card is that with the temporary work visa the stay, although possibly extended multiple times, is considered temporary. A green card gives a foreign national Lawful Permanent Residence in the U.S., which allows one to work and live in the U.S. permanently without the restrictions imposed on a temporary work visa. After having Lawful Permanent Residence for five (5) years, the individual may apply to become a United States Citizen.
About some other differences between a temporary visa and a green card
Another significant difference between a temporary work visa and a green card is the requisite standard for eligibility. With an O-1 visa, many up and coming professionals can successfully petition for such status. On the contrary, with the EB1.1 Extraordinary Ability Petition the standard is one in which the individual must be among the very top in the industry. Hence, the standard for the green card is much higher than that of the temporary work visa. We suggest having an experienced immigration attorney advise you on whether your experience and accomplishments merit potential Green Card eligibility.
Finally, there is a significant difference in cost and processing times associated with a temporary work visa and a petition that may lead to a green card. In addition to the cost difference required as to the immigration filing fee for either application, the green card petition requires more labor on the part of the attorney and there is an additional premium over the services charged for such a petition versus a temporary work visa. Also, Immigration processing times for a temporary visa may be anywhere from three to four months; whereas, the average time for an Extraordinary Ability petition to be processed may take from nine to twelve months. We discuss further below.