The following is an introduction to the visa:
Visa is a kind of license issued by a government agency for foreigners applying for entry, exit or transit according to the provisions of domestic laws.
The visa is usually attached to the passport or other international travel documents held by the applicant. Under special circumstances, valid passports or other international travel documents can be written on a separate sheet. With the progress of science and technology, some countries began to issue electronic visas and biological visas, which greatly enhanced the anti-counterfeiting function of visas.
Visas in countries around the world are generally divided into entry visas and transit visas, and some countries also have exit visas. Visas in China are divided into entry visas and transit visas.
There are many kinds of visas in different countries. According to the identity of the holder, the type of passport and the reason for the visit, visas are generally divided into four types: diplomatic visas, courtesy visas, official visas and ordinary visas. Some countries classify visas into travel, visit, work, study and residence according to the reasons of visitors.
Refer to Baidu Encyclopedia -Visa for the above information.