What kind of server are there? Ordinary users usually do not think about such issues, considering them the prerogative of system administrators and programmers. However, often enough, when they are invited to connect to some server or install the appropriate software on their own computer, problems begin. Next, we will try to consider what exactly is meant by the term “server”, define the types of servers and describe the main purpose of each type, trying not to delve into the intricacies of the technical aspects, but in simple terms.
What does the server do and what is it generally understood?
In general, strictly speaking, based on the interpretation of such respected sources as the same "Wikipedia", initially the server refers to special software installed on one or more computers, in order to provide increased performance when performing certain tasks or to access various services and opportunities that arise when using network connections or when organizing an Internet connection.
However, among users, for sure, there are also those who heard jokes of programmers and system administrators that, they say, the server crashed. Of course, in this case we are not talking about the fact that the computer fell off the shelf. It describes the problem of failure of the installed software.
On the other hand, today it is really very common to understand servers as single or integrated computer terminals that perform completely different functions. For example, their hard drives can be used to store files or databases. Another purpose - the organization of connections over local or virtual networks with access to the Internet, etc. In the case of common tasks performed, the software can vary quite strongly, as well as vice versa.
Finally, in a separate category, whole server operating systems can be distinguished, which play a dual role, acting both as the server to which other terminals and users connect, and the role of the operating system.
Speaking about what kind of server there are, it is necessary to note one more important point. According to the principle of operation, if it comes exclusively to software, almost all known servers operate on the basis of a client-server chain. In other words, either other computers on the network are connected to one central resource or a computer device acting as a server, or user requests are addressed to them. Depending on the purpose, the servers can be grouped by type, however, the classification adopted today is extremely vague, since the capabilities of server systems are constantly expanding and improving. In addition, there are some types of servers that cannot be assigned to only one category.
The simplest server classification
You can separate servers into groups and subgroups for a very long time, and it takes a lot of time to do this. Nevertheless, let's see what kind of servers are, if we consider them from the point of view of some simplified classification. Among their entire myriad of species and subspecies, several categories can be singled out separately, summarized by some common features, purpose, and tasks performed. The most famous today are the following:
- Workgroup servers and domain controllers
- network servers and services;
- mail servers and data exchange servers;
- application servers
- database servers
- Web servers
- file servers and FTP servers;
- terminal servers.
Workgroup and domain controller
These two types of servers are interconnected very closely. The first category is a unified solution for managing other computers in a network and delimiting user rights regarding access to certain functions of the system or installed software.
The domain controller server has a strictly hierarchical structure and is designed to authenticate users based on the use of Active Directory services to save user information and manage domain resources.
Network Servers and Services
Among network servers, you can find many subspecies. The simplest network server, although in fact it is not, can be called the most ordinary router in the form of a modem or router. However, it is he who performs the distributing and directing function when connecting users to the same network and sending requests to certain resources or sites.
DNS servers act as converters of user queries; therefore, they are called domain name servers. You, for example, when trying to access a page on the Internet do not enter its unique IP address? The server transforms the entered alphanumeric combination into the desired combination on its own. Thus, you do not need to remember the addresses of each page, which on a single resource can be a huge number, but it is enough to know only the main name of the resource.
As you know, when accessing the Internet, special protocols are used. In turn, DHCP servers are very closely connected with them.
In order not to delve into the essence of their functioning, it’s enough to note that even a provider will not be able to provide you Internet access using the TCP / IPv6 protocol if it does not have a server of the corresponding sixth modification.
Among network servers, proxy servers occupy a special place, since they were originally designed to ensure the security and anonymity of users who connect to them during Internet surfing. By the way, it was on the basis of proxy technology that at the time most of the currently known VPN clients were developed, allowing you to change the IP addresses of user computer and mobile devices, bypassing all kinds of regional restrictions and restrictions.
It turns out that the connection to the proxy server is directly made only from the user terminal, and the request for the resource does not go through the server, because after its adoption the server sends a completely identical request to the desired site or page, but on its own behalf. Thus, it becomes simply impossible to calculate your territorial location by belonging to a specific region of the unique IP address of your computer.
Finally, in the organization of local area networks, servers are directly involved. So, for example, the role of a server can be played by one powerful (or not so) terminal through which all other machines are interconnected. But here the connection organization used, called the network topology, is of particular importance.
The most commonly used star scheme or mixed connection types. In addition, along the way, one more interesting fact can be noted. For example, with such an organization, operating systems are not always installed on subsidiary terminals, and you can work on them only by using the OS installed on the central server. Thus, it becomes clear why server operating systems are also included in one of the subspecies of the servers.
Finally, all sorts of remote access servers can be classified in the same category, which allow you to manage computers separated by large distances, which usually may require either an IP server or the address of a remote terminal.
As for network services, at the moment there are a lot of them. Some of the most striking examples are NTP time synchronization services, servers that process information about hosts or connected users, SNMP monitoring tools, etc. By and large, they all belong to the so-called universal servers.
Mail servers and data exchange servers
Now let's see what kind of data referral servers are. Among them, too, one can meet many interesting things. It seems, with mail servers and so everything is clear. Just go to any resource that provides email services, and everything will become clear right away.
However, if we are talking about organizing mail inside a local corporate network, you can also use special software that allows, for example, to specify the company’s website as the main domain, although in fact it does not provide electronic mail services. Roughly speaking, you work for a company with the code name "111". By installing the appropriate software, you can get an e-mail address like I_am@111.com.
But among all this diversity, the most popular were and remain systems based on the POP3, SMTP, and IMAP protocols.
As for the data exchange servers, for sure, everyone knows about them. Quite often, if we talk only about software, such technologies are used on all kinds of file hosting services like DepositeFiles, Turbobit, etc.
File and FTP Servers
FTP servers are some of the oldest since the advent of the Internet. From at the same time it can be attributed both to file servers and to data exchange servers, since both files are stored on them, and you can also download or upload to remote storage. For this, the universal FTP protocol is used for transferring files.
Well, with file servers everything is clear. Their main purpose is reduced solely to data storage, and the role of such a server, in principle, can be played by any computer or group of terminals on which there are hard drives of a sufficiently large volume. Such servers are universal for the simple reason that they do not depend on the regional location of a particular computer terminal and can be scattered around the world.
Application servers
This type of server is a software repository to which a user request can be made at any time and then use the available software for their needs without the need to install programs on their own computer. One of the varieties of such solutions can be called specific server solutions like “1C”, when the server part is installed on one terminal, and the client part is installed on the daughter machines. Access to the main functionality of the program after passing authentication of registered users is made from your own computer.
The same thing, by the way, can be observed in the case of working with cloud services like Office 365 or Chrome browser extensions.
All sorts of game servers can be included in the same category (for example, the popular platform for Minecraft or the same Steam service).
Database servers
As a rule, application servers are in very close contact with database servers, and sometimes they do not work without them at all. The purpose of the latter is not only to store, but also to process huge amounts of information that are accessed by installed programs during operation. Among the most famous servers of this type are MySQL, SQL Server from Microsoft, Oracle and some others.
Print servers
Print servers are narrowly targeted platforms that enable the use of a single printing device for multiple computers simultaneously. At the same time, the correct print queue is built on a server of this type, the priority of printing documents is set, etc. All this allows you to partially free the RAM of computers on which connecting your own printers can overload system resources.
Terminal servers
Finally, terminal servers can be a single powerful computer or even entire cluster systems that share their computing resources if weak machines or network terminals cannot handle the processing of computations due to their limited configuration.
Recently, just such technologies are gaining strength, and for ordinary users connecting to such systems, the need to upgrade their own PC in order to increase productivity disappears.