Part-Time: When you are enrolled in classes and work for 20 hours or less per week, it falls under the category of part-time Curricular Practical Training. Consequently, the authorization on your I-20 form should clearly indicate permission for part-time training, and it is crucial to ensure that your work hours do not exceed 20 hours per week.
Full-Time: Engaging in employment exceeding 20 hours per week is classified as full-time Curricular Practical Training, and accordingly, the employment authorization noted on your I-20 form should explicitly state permission for full-time training. There is no set duration limit for participating in full-time Curricular Practical Training. However, if you engage in it for twelve months or longer, you will become ineligible for any form of Optional Practical Training, including post-completion practical training.