Computer networks are the modern communication technology and computer technology combined with the product, so-called computer network, the computer is located in different geographical areas and dedicated external device communication lines interconnected into a large-scale, strong function of the computer application system, so that many The computer can easily transfer information to each other, to share hardware, software, data, information, resources, people set up a computer network for the purpose of sharing resources between computers, and therefore, the number of network resources available determines the existence of the price of a network, scale computer networks are of different sizes, the large global coverage, small can be constituted only by an office of two or several computers. Generally, the larger the network, including the computer, the more abundant network resources it provides, the higher its value. From the definition of a computer network involves several aspects: At least two computers interconnected; line media and communications equipment; network software, refers to the communication protocols and network operating systems. Application of computer networks is changing the way people work and lifestyle, is further cause changes in the worldwide industrial structure, promoting the development of the global information industry, it has been seen: computer is, the more wide range of applications, the greater the need to interconnect together to form a network. Adjustments in IT development today, is based on a computer network, the network is the computer has been widely accepted. Nanjing site building zczxweb.cn