The English name of the server is "Server", which refers to a dedicated computer that provides some kind of service for the client in the network environment. The server is installed with a network operating system (such as Windows 2000 Server, Linux, Unix, etc.) and various server applications. A computer for system software (such as web services, email services). The "client" herein refers to a computer on which an operating system used by a general user such as DOS or Windows 9x is installed. The processing speed and system reliability of the server are much higher than that of a normal PC, because the server generally works continuously in the network. The ordinary PC crashes and the big deal is restarted, and the loss of data is limited to a single computer. The server is completely different. Many important data are stored on the server. Many network services run on the server. Once the server fails, a lot of data will be lost, and the damage is difficult to estimate. The functions provided by the server are as follows. Proxy Internet access, security verification, and e-mail services will all be ineffective, causing network paralysis and the requirements for server reliability.

According to different classification standards, servers are divided into many types.

1, according to network size

According to the network size, the server is divided into a workgroup level server, a departmental level server, and an enterprise level server. Workgroup-level servers are used in networked computers with a few dozen or so small networks that require less processing speed and system reliability. The hardware configuration is relatively low and the reliability is not very high. The departmental server is used for medium-sized networks with networked computers in the range of about 100 units, such as processing speed and system reliability. The hardware configuration is relatively high, and its reliability is at a medium level. Enterprise-class servers are used in large networks with more than a few networked computers and the highest processing speed and data security requirements. The hardware configuration is the highest and the system reliability is the highest. It should be noted that the boundaries between these three servers are not absolute, but rather vague. For example, the difference between a workgroup server and a departmental server is not too obvious, and some are simply referred to as "workgroups/departments." Level" server.

2, divided by structure

According to the structure of the server, it can be divided into a CISC-based server and a RISC-based server. The CISC architecture mainly refers to servers using Intel architecture technology, which is often referred to as "PC server"; RISC architecture servers refer to servers using non-Intel architecture technology, such as RISC such as Power PC, Alpha, PA-RISC, Sparc, etc. CPU server. The performance and price of a RISC-based server is much higher than that of a CISC-based server. In recent years, with the rapid development of PC technology, the technology gap between IA architecture server and RISC architecture server has been greatly reduced, users are basically inclined to choose IA architecture server, but RISC architecture server is in large, key application areas. Still in a very important position.

3, by purpose

According to the purpose of use, the server can be divided into general-purpose servers and dedicated (or "functional") servers, such as Shida's Bohai series of functional servers. A general-purpose server is a server that is not designed for a particular service and can provide various service functions. Most of the current servers are general-purpose servers. A dedicated (or "functional" server is a server designed specifically for one or a few functions, and in some respects is different from a general purpose server. If the CD image server is used to store the CD image, you need to have a large capacity, high speed hard disk and CD image software.

4, by appearance

According to the appearance of the server, it can be divided into desktop servers and rack servers. Some desktop servers use chassis that are roughly the size of a vertical PC desktop, and some use a large-capacity chassis. Like a large cabinet, the rack-mounted server does not look like a computer, but a switch. 1U (1U = 1.75 inches), 2U, 4U and other specifications, is a 1U rack server. The rack server is installed in a standard 19-inch cabinet. Having said that, what kind of server should I buy? I can't generalize on this issue, but should adapt to local conditions. If your network is a small network of dozens of computers, users will not access a large number of servers in a short period of time, and a PC server of 10,000 to 20,000 yuan or 20,000 to 30,000 yuan can be used. If your network consists of hundreds or even thousands of computers, users need to access the server frequently, you need to buy department-level or even more expensive enterprise-class servers with prices ranging from 30,000 to 50,000 yuan or even 60,000 to 80,000 yuan.