What do you think is the difference between the immigration companies established in China and China and the entry-exit administration and immigration bureau?

The China Exit-Entry Administration can only approve the issuance of your China passport, Hong Kong, Macao and Taiwan passes and other overseas documents, and cannot handle foreign visas for you. The immigration company can help you apply for a China passport or a Hong Kong, Macao and Taiwan pass, but the immigration company has no right to directly issue you a certificate of going abroad. The foreign immigration bureau is only responsible for examining your visa application, but it has no right to issue a China passport or a Hong Kong, Macao and Taiwan pass for you. China's Exit-Entry Administration and Foreign Immigration Bureau are government agencies, not commercial organizations, while immigration companies are private commercial organizations, which are different from government agencies.