Visa . What is F 1 visa? What is M1 visa? What is J 1 visa? What are the differerce among them?

r u in US ?
if so M1 visa is a type of student visa for full time students in an academic or language program.
F1 students may stay in the US for the full length of their academic program plus 60 days. F1 studens must maintain a full time course losa and complete their studeies by the expiration date listed on the I-20 form.
J1 visa is issued for students needing pratical training that isnt available in their home country to complete their academic program.the J1 visa obligates the student to return to their home country for a minimum of two years after the end of their studenies on the US before being eligible to apply for an immigrant visa