It belongs to all levels of the host name from the domain name and host name assigned to this common composition. When writing in accordance with the ascending order, top-level domain on the far right, assigned to the host name on the left, between levels with names separated. In the domain name system common top-level domain is divided organizational models, such as .com domain name because it is com TLD may decline it is a company's Web site address in addition to other top-level organizational models top-level domain name corresponding to the geographical mode. For example .com.cn this domain because of its top-level domain is cn can decline it is China's website address. Management of top-level domains are assigned designated management agency governing bodies to continue its management domain division, which is divided into two domains and the management of secondary domain granting regulatory agencies their subordinates so the layers formed subdivision domain-like hierarchical structure. Hualay zczxweb.cn