What is "status"?
Status is doing what you are authorized to do while you are in the U.S. based on the immigration category on which you entered.
The regulation 8 CFR 214.2(f)(5) Duration of status states:
- General. Except for border commuter students covered by the provisions of paragraph (f)(18) of this section, an F-1 student is admitted for duration of status. Duration of status is defined as the time during which an F-1 student is pursuing a full course of study at an educational institution approved by the Service for attendance by foreign students, or engaging in authorized practical training following completion of studies, except that an F-1 student who is admitted to attend a public high school is restricted to an aggregate of 12 months of study at any public high school(s). An F-1 student may be admitted for a period up to 30 days before the indicated report date or program start date listed on Form I-20. The student is considered to be maintaining status if he or she is making normal progress toward completing a course of study.
- Change in educational levels. An f-1 student who continues from one educational level to another is considered to be maintaining status, provided that the transition to the new educational level is accomplished according to transfer procedures outlined in paragraph (f)(8) of this section.
- Annual vacation. An F-1 student at an academic institution is considered to be in status during the annual (or summer) vacation if the student is eligible and intends to register for the next term. A student attending a school on a quarter or trimester calendar who takes only one vacation a year during any one of the quarters or trimesters instead of during the summer is considered to be in status during that vacation, if the student has completed the equivalent of an academic year prior to taking the vacation.
- Preparation for departure. An F-1 student who has completed a course of study and any authorized practical training following completion of studies will be allowed an additional 60-day period to prepare for departure from the United States or to transfer in accordance with paragraph (f)(8) of this section. An F-1 student authorized by the DSO to withdraw from classes will be allowed a 15-day period for departure from the United States. However, an F-1 student who fails to maintain a full course of study without the approval of the DSO or otherwise fails to maintain status is not eligible for an additional period for departure.
Program completion for immigration purposes is deemed to be the final day of the semester for students enrolled in a semester-long course which meets on regularly scheduled, specified days and times for the duration of the semester. Students enrolled in condensed courses are deemed to have completed their programs on the last day of required attendance during their final semester.
GRADUATE STUDENTS WITH THESIS/PROJECT REQUIREMENTS
For those students who are enrolled only in graduate thesis or research credits and who have met all other course requirements in a previous semester, program completion is calculated from the date of thesis or project defense not the last day of the semester date. The official program completion date for these students is either (1) two months from the defense date or (2) the approval date on the Report of Thesis/Dissertation Defense form or the Report of Project Defense form when signed by the academic department chair, whichever is earlier.
You can read the official policy memo here.