F1签证和J1签证详细比较（正在申请I20，看到这个东东随手粘到地里了）

Comparison of F-1 and J-1 Visa Types

Topic F-1 J-1 Eligibility Restrictions None. Cannot be self-funded unless participating in an exchange program pursuant to a formal written agreement between educational institutions or governmental offices. On-Campus Employment Available up to 20 hours per week when school is in session and 40 hours per week during annual school holidays. Same as F-1. Off-Campus Employment Yes: Can be authorized for unforeseen financial hardship, Curricular Practical Training, or Pre- and Post-completion Optional Practical Training Yes: Can be authorized for unforeseen financial hardship or Academic Training. Practical/Academic Training Types 1) Curricular Practical Training (CPT). 2) Optional pre- or post-completion Practical Training (OPT). Optional or Required Academic Training may take place before or after graduation Time Limits for Practical/AcademicTraining Curricular: None, although if you use more than 12 months of full-time CPT, you lose your eligibility for any OPT. Optional (Pre- and Post-completion, combined):12 months maximum for each higher degree earned.Possible "Cap Gap" extension.One-time extension of 17 months is available to certain STEM degree recipients. Note: In general, the period of Academic Training may not exceed 18 months or the amount of time spent in the academic program, whichever is less.Nondegree: 24 months maximum, including the academic program itself. Degree: Pre-doctoral, 18 months maximum Post-doctoral, 36 months maximum (for post-doctoral research only).Part-time Academic Training counts the same as Full-time Academic Training. Requirement of Job Offer for Practical/Academic Training Curricular: Yes Pre-completion Optional: Recommended Post-completion.Optional: No . From 1point 3acres bbs Pre-Completion: Yes Post-completion: Yes. Must have job offer within 30 days of completion of studies and you must apply before you complete your program as well. Authorization from USCIS for Practical/Academic Training Curricular: Not required. Authorization is obtained from Duke Visa Services advisor. Pre- and Post-completion Optional:Required before student may begin work. Authorization takes 3-4 months. None required. Authorization is obtained from Duke Visa Services advisor. Possibility of Changing Status Yes, fairly easily. It depends. May be problematic for students subject to the 2-year home residency requirement. Work Authorization For Spouse None possible. Yes, with evidence that salary is not needed to fund stay, and it requires USCIS approval. Enrollment for Spouse Cannot enroll for credit bearing courses. Can enroll for credit bearing courses. Insurance Requirement per Visa Status None per visa category. Although the University requires all students to carry insurance, this is not a federal requirement, nor does it apply to spouses. Yes, for J-1 students and all dependents. Willful failure to maintain adequate health insurance as defined by federal regulations will result in the student's termination from the J-1 program, thus also terminating his/her J-1 status. Permission to Stay in U.S. after Completion of Studies 60 days granted automatically. 30 days granted automatically.

求解释。求详解，尤其是找工作那块