The names left by Ac-scientific research organization com-commercial organization, industrial, commercial, financial and other enterprises edu-educational institution, educational institution government-government entity, government department military and military institution arpa-from ARPANet, ARPANET (computer network established by the Advanced Research Projects Agency of the US Department of Defense) are used for the internal functions of the Internet-Net- network operation and service center. Internet, information center (NIC) and operation center (NOC) organizations-biz-web business guide for other organizations and various non-profit organizations. Suitable for commercial companies (note: biz is the customary abbreviation of business) info-infomation, an enterprise providing professional information services, with a common top-level name-a name suitable for doctors, lawyers, accountants and other professionals. Coop-cooperation, generic top-level domain name suitable for individual registration, aero-aero, private top-level domain name suitable for commercial cooperatives, museum-museum, and private top-level domain name suitable for air transportation. Mobi, a museum-specific top-level domain -Tel is used for mobile phone networks in Asia -Int- International organizations are used for telephones, and CC, an international organization, was originally the abbreviation of "Corcos (Keeling) Islands", but it can also be regarded as the abbreviation of "commercial company", so it was opened as a global international top-level domain name, mainly used in the commercial field. Short, easy to remember, beautiful and easy to input, it is a new generation of domain name rookie TV-originally the country code top-level domain name of Tuvalu, a Pacific island country, but because it is also the abbreviation of "TV", it has now been opened as a global international top-level domain name, mainly used in the fields of audio-visual, film, television and other global radio stations. Us-type stands for the United States, and the number of registered tourists is the second in the world-tourism domain name, international domain IDV-is used for individuals.