签证是主权国家准许本国公民或外国公民出入境或经过国境的一种许可证明。它一般由发证国家签在申请人的护照上,由发证国驻华使、领馆或其他代行签证事务的机构办理。签证是实施出入境管辖的一项主要手段,已发展成为一种法律制度。签证有许多种,各国都有根据申请者的不同身分和不同的入境目的,发给相应的签证。 A visa is a permit issued by a sovereign country to allow its own citizens or foreign citizens to enter or exit the country or pass through the border. It is generally signed by the issuing country on the applicant’s passport, issued by the issuing country embassy, ​​consulate or other agencies acting on behalf of the visa. Visa is a major means of implementing immigration control and has developed into a legal system. There are many kinds of visas. All countries issue visas according to their different identities and different immigration purposes.