We explain what a server is, its main characteristics and what it is for. Also, what is a web server, classification and examples.
What is a server?
In computing, a computer that is part of a computer network and provides certain services to the rest of its computers, called stations or clients, is known as a server. Said computer It must have a specific application capable of meeting the requests of different clients and provide them with a timely response, so that in reality several simultaneous servers (software) can operate within the same physical computer (hardware), as long as they have the necessary logistical resources.
Servers operate based on a client-server communication model (or “architecture”), dividing the tasks among the providers of available resources, thus offering its clients the opportunity to share data, specific information and access to certain software and hardware resources, such as a specific application or peripheral. This is how, for example, web pages and email services work.
Commonly, servers They can be classified according to their availability into dedicated and shared. Dedicated servers are those that have all their hardware and processing resources to serve customer requests; while shared servers are those that, in addition to receiving requests from clients through the network, serve processes locally, outside the network.
Characteristics of a server
Since servers are computers in charge of meeting the demands of network clients, one of their main characteristics is that they must have their resources constantly available so that the network is operational all the time. I mean, should always be on, always available. This is why sometimes a web page or its resources cannot be loaded: if a server crashes or crashes, a certain segment of the network that it is in charge of will no longer be available to its customers.
On the other hand, the servers they are usually high-end computers, endowed with sufficient processing capacity to attend numerous customer requests with a minimum delay range. This also implies having a constant supply of electricity and other physical resources to guarantee its operability. In fact, in many cases, servers are stored in very well-conditioned compartments, even climatically: in a sufficiently cool and dust-free environment, overheating of the system is avoided.
What is a server for?
The servers, as we have said, are in charge of meeting the requests of the clients of a certain network, and managing the resources available to it so that each client can access the information or peripherals they need. In this sense, servers can have very different functions, such as:
- File servers. They store the files or files of information and feed them to a network.
- Active Directory / Domain Servers. They manage information related to the network, its users, computers, and internal groups.
- Print server. It manages a set of printers available to a network, granting access to them and managing the print queue.
- Mail server. It manages the flow of e-mail between, from and to the clients of a network, sending and receiving messages and storing their history.
- Proxy server. Its role is of backup, storing for a time and in memory a copy of the web pages available for the network, to accelerate the access to them or to allow the recovery of data if the original one goes down.
- Web server. It stores the content necessary for one or more web pages and manages the orderly access to it, so that the clients’ browsers can “render” a website.
- DNS server. 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 specific user information 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 (massive video games, generally).
Web server
Web servers are programs (software) for daily use on the Internet, which intermediate between the server where the data requested by the client is hosted and their own computer, allowing connections through various data protocols, such as the well-known HTTP (HyperText Transfer Protocol, or Hypertext Transfer Protocol). In other words, they are programs that mediate between the browser of an Internet user and the place where the information he is looking for or needs resides.
This term is also used to refer to the computer itself (hardware) on which the files that make up a website are stored, along with the software necessary to comply with the web data connection.
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Types of web servers
Web servers can be of two kinds, depending on their content:
- Static servers. This is the name given to the computers where the information that the user seeks is stored and the HTTP server that responds to the data request protocols. The requested files are sent as they are stored, whether or not there are errors, and that is where their name comes from.
- Dynamic servers. In this case, these are servers identical to the static ones, but which 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.
Examples of web servers
Some of the most used web servers are the following:
- Nginx. A web server and Proxy developed by the eponymous company 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 the C language, available under the GNU General Public License (free software).
- Tomcat. A 1999 Apache distribution, also known as Jakarta Tomcat, which operates on the principle of servlets (Java).