Consular visa stamp
The consular visa stamp represents permission to travel to the US. It indicates the date until which a student may enter or re-enter the US. It does not indicate how long the student may remain in the US. That amount of time will be specified on your form I-94 and on your form I-20. Visas may be obtained only outside the US at an American Embassy or Consulate.
F-1 visa status
International students usually study in the US on either an F-1 visa, which requires full-time study. Students obtain an F-1 visa by visiting a US Embassy or Consulate and presenting a form I-20 certificate of eligibility issued by MIAD. On the form I-20, OIPS certifies to the Consul and Immigration officials that the student has adequate English language proficiency and adequate financial resources, and is academically qualified to attend the school to which he or she has been accepted.
On these forms, an International Programs & Services certifies that a student has adequate English language proficiency and adequate financial resources, and is academically qualified to attend the school to which he or she has been accepted. Students cannot let the date of completion of studies on these forms expire, and must apply for an extension 60 days in advance.
An I-94 Form, which is also called a Departure Record, is issued to students upon their arrival in the US by an Immigration officer. The form, which is a white card usually stapled to your passport, is generally marked "D/S" (duration of status) by the Immigration officer at the port of entry. The "D/S" means that you will be in legal status only as long as you are a full-time student pursuing the same degree that is specified on your I-20 form and your document is valid. Please pay attention to the completion date that appears on the I-20 form. If you ignore this date and let your form expire, you will lose your legal status. If you find that you will not be able to complete the program by that date, you should contact OIPS at least 60 days before the I-20 is about to expire in order to apply for an extension.
Before you come to the US your government issues you a passport that allows you to leave and re-enter your country. Your passport must be valid at all times. Before your passport's expiration date you must have it revalidated by your country's nearest Consulate. In order to ensure a timely extension it is wise to apply as far in advance as your home country allows. If you are mailing forms to a government office, never mail your passport.
United States Citizenship and Immigration Services.