What is the definition for a business visa?什么是商务签证？
Business visas refer to the certificate which a person needs to go to another country to make investment, do business, attend meetings, exhibit, or discuss about labors.商务签证主要指有关人员因公务或者个人原因去某国从事投资、贸易、会议、展览、劳务等方面事务进行实地考察或洽谈，这类人员进入某国需持商务访问证。
What qualifications does a person need to apply for a business visa?办理商务签证需要哪些条件？
Generally speaking, the Immigration Bureau will require the person who is applying for a business visa to its country to be phsically healthy, no criminal record, and no threat to the national security.移民局要求商务考察者身体健康，无刑事犯罪记录，对某国的国家安全不会构成威胁。
Some countries demand the person who is applying for a business visa to have certain economic capability to support himself or herself in the host country.有些国家要求申请商务签证的人有足够的经济能力维持自己在某国逗留期间的各种开支。
Valid and true reasons are needed for the person who is applying for a business visa to prove that his or her visit to that country is true and without ill intention.商务签证的申请人在提出申请时，需要有效商务理由，来证明他去某国访问是真实的，没有任何不良意图。
The officers usually need the person who is applying for a business visa to provide enough evidence to confirm that there is a really business necessity for him or her to go to another country; 签证官一般需要这类签证的申请人提供足够的证据，证明他去某国确实有商务的需要。
therefore an invitation letter from that country is necessary.因此，一封来自某国的邀请函，是最基本的一份文件。