The term "physical isolation" refers to the fact that an intranet is not directly or indirectly connected to a public **** network. The purpose of physical security is to protect hardware entities such as routers, workstations, network servers, and communication links from natural disasters, vandalism, and wiretapping attacks. Only by physically isolating the intranet from the public **** network can the internal information network of party and government organizations be truly assured against hacker attacks from the Internet. In addition, physical isolation also delineates a clear security boundary for the government intranet, making the network more controllable and facilitating internal management.