The English name of a Server is "server", which refers to a special dedicated computer that provides various services for clients in a network environment. In the network, the server undertakes the key task of data storage, forwarding and publishing, and is an indispensable part of various networks based on client/server (C/S) mode. In fact, there are no hard and fast rules for server hardware, especially for small and medium-sized enterprises. Their server may be a PC with good performance, but the only difference is that a special server operating system is installed in it, so such a PC plays the role of a server, commonly known as a PC server, and completes various required server tasks. Of course, because there is a far gap between PC and specialized server in performance, it is conceivable that the server served by PC can not undertake high-load tasks in terms of network connection performance and stability, and can only be applied to small networks with simple tasks. This article and the following articles introduce not this kind of PC server, but various specialized servers.

However, on the other hand, the server is actually a kind of computer after all, and it is also developed from PC. When the network was not very popular in the early days, there was no such name as server. At that time, there were only two categories in the whole computer field: mainframe computers and microcomputers. However, with the development and popularization of the network, especially the local area network, the middle-level computer "server" began to be accepted by the industry, and it continued to develop with the popularization and development of the network. However, the server is not exactly the same as the computer we usually see. Otherwise, among so many server manufacturers in China, few can really produce medium and high-end servers, and even few in the world have this strength. Dell can only produce some middle and low-end servers, which are caused by the special requirements of servers. These are the four main characteristics of the server (often referred to as the "four characteristics"). Although the server is composed of motherboard, CPU, memory, hard disk and so on. Just like PCs, these hardware are not used by ordinary PCs, but are specially developed for server environment, although they are basically similar in appearance. Because of this, the price of servers is usually high, ranging from tens of thousands of mid-range servers to tens of millions or millions of high-end servers. Of course, at present, we also see that many well-known servers are priced at only a few thousand yuan.