Each Country has Different Terms and Condition for Student VISA.
In Russia, this type of visa is given to students who are going to study in Russia. The visa is given for the whole duration of the study program, and is single-entry. To obtain student visa, one needs an official invitation from an authorized organization in Russia (school, college, university, etc.)
According to Chinese laws, foreign students studying in China should have student’s visa for entrance. With the school admission notice, the required document of visa application for study in China (Form JW201or JW202), students apply for the student’s visa in the Chinese embassy or consulate in their own countries. After the new regulations which take effect on September 1, 2013, students who plan to study in China for over 6 months will be issued an X1 visa, and those for less than or equal to 6 months will be issued an X2 visa. The Chinese embassy or consulate has full authority to make the decision if the applicant should be issued a visa or not.
The school admission office of international students will send the school admission notice (letter of acceptance) and the required document of visa application for study in China (Form JW201or JW202) to the student after application is accepted. Both of them are very important documents for international students to study in China. Not only they are used for the application of the student visa, but also for the renewal and extension of the student visa after the student registers in the university. Students should keep the original copies of both documents and bring them to China. Photocopy of these documents are not qualified for the visa affairs. Since the student’s visa has a period of validity, students should arrange the trip reasonably and register at the university on time. Arriving in China too early may result in visa expires before the indicated registration time. Late arrival always disturbs the arrangement of the study schedule.
There are different rules and regulations in different countries. You can visit The AllSol for more details regarding this.