آیا تا به حال کسی بوده که دانشگاه بهش گفته باشه هم می تونی F1 بگیری هم J1؟ با این همه توصیف کدومش بهتره؟
راستی هر دوتای اینها حتما single entry هستند؟
این هم مشخصات دو نوع ویزا:

F-1 Student Visa
F-1 is the most commonly used visa by students who come to the United States to pursue full-time graduate or undergraduate study without full sponsorship.
The post-graduation training for F-1 students is limited to 12 months but no job offer is required to apply for work permission within the United States.
F-2 dependents of F-1 visa holders are not eligible to apply for work permission in the United States.
Students on F-1 visas are not subject to a potential two-year home country physical presence requirement.

J-1 Student Visa
If students receive full funding from an academic department, they may be eligible to apply for a J-1 student visa.
The length of post-graduation academic training for J-1 students goes up to 18 months (36 months for postdoctoral training) and requires a job offer.
J-2 dependents of J-1 visa holders are eligible to apply for work permission in the United States and enroll as full-time students.
Please note that J-1 visa holder may be subject to a potential two-year home country physical presence requirement.