What is a server?

We explain what a server is, its main features and what it is for. Also, what is a web server, classification and examples.

1. What is a server?

In computing , it is known as a server (English server) to a computer that is part of a computer network and provides certain services to the rest of the computers of the same, called in turn stations or customers. Said computer must have a specific application capable of responding to the requests of the different clients and providing them with a timely response, so that in reality within the same physical computer ( hardware ) several simultaneous servers ( software ) can operate , provided they have the necessary logistic resources.

The servers operate based on a client-server communication model (or “architecture”), distributing the tasks among the providers of available resources , thus offering their clients the opportunity to share data , specific information and access to certain resources of software and hardware, such as a specific application or peripheral. This is how web pages and email services work, for example .

Commonly, servers can be classified according to their availability in dedicated and shared . Dedicated servers are those that have all their hardware and processing resources to meet customer requests; while shared servers are those that, in addition to receiving requests from clients through the network , attend processes locally, outside the network.

2. Server Features

Since the servers are computers responsible for meeting the demands of the clients of the network, one of its main characteristics is that they must have their resources constantly so that the network is operational all the time. That is, they must always be on, always available . This is the reason why sometimes a web page or its resources cannot be loaded: if a server collapses or breaks down, a certain segment of the network under its charge will no longer be available to its clientele.

On the other hand, the servers are usually high-end computers , equipped with sufficient processing capacity to meet numerous client requests with a minimum delay. This also implies having a constant supply of electricity and other physical resources to guarantee its operation. In fact, in many cases, the servers are stored in compartments very well conditioned for it, even climate: in a sufficiently cold and dust-free environment, overheating of the system is avoided.

3. What is a server for?

The servers, as we have said, are responsible for responding to the requests of the clients of a given network, and managing the resources available to it so that each client can access the information or the peripherals it needs. In that sense, servers can have very different functions, such as:

• File Servers They store the files or information files and feed them to a network.
• Active Directory / Domain Servers. Manage information related to the network, its users , computers and internal groups.
• Print Server Manage a set of printers available for a network, granting access to them and managing the print queue.
• Mail server. It manages the email flow between, from and to the clients of a network, sending and receiving messages and storing their history.
• Proxy server Its role is backup, storing a copy of the web pages available for the network for a while and in cache memory , to accelerate access to them or allow data recovery if the original falls.
• Web server. It stores the necessary content for one or several web pages and manages the orderly access to it, so that the clients’ browsers can “render” a website.
• DNS server It stores the information necessary to associate a domain name with a series of IP addresses of the computers linked to it (its web servers).
• DHCP server Responsible for assigning dynamic (changing) IP addresses to clients that connect to a network.
• FTP server Stores timely information of users and allows private access to it between computers.
• Game Server Those specifically dedicated to storing information so that customers can access a recreational program at the same time (mass video games, generally).

4. Web server

Web servers are programs (software) for everyday use on the Internet , which intermediate between the server on which the data requested by the client and their own computer are hosted , allowing connections through various data protocols, such as the known HTTP(HyperText Transfer Protocol, or Hypertext Transfer Protocol ). That is, these are programs that mediate between a user’s Internet browser and the place where the information they are looking for or needs resides.

This term is also used to refer to the computer itself (hardware) in which the files that make up a website are stored , together with the software necessary to comply with the web data connection.

5. Types of web servers

Web servers can be of two kinds, depending on their content:

• Static servers. The computers where the information that the user is looking for and the HTTP server that responds to the data request protocols are called. The requested files are sent as they are stored, whether or not there are errors, and from there comes their name.
• Dynamic servers. In this case they are identical to static servers, but they contain additional software (such as applications and databases ), which allows them to update the information requested by the client before sending it through the web.

6. Examples of web servers

Some of the most used web servers are the following:

• Nginx A web server and proxy developed by the company of the same name in 2004.
• Apache. An open source HTTP web server, developed in 1995 and maintained by a community of users that make up the Apache Software Foundation.
• Internet Information Services or IIS. A web server and set of services designed for Microsoft Windows that was originally included in its NT version.
• Cherokee A multiplatform web server written in C language, available under the GNU General Public License ( free software ).
• Tomcat A 1999 Apache distribution, also known as Jakarta Tomcat, which operates under the servlets (Java) principle.