When we think of a server, we automatically picture an enormous computer, the size of a room, capable of controlling a multitude of functions. The real meaning of the term ‘server’ is however much wider and goes beyond the logic of hardware.
In IT, the term can also be applied to software used to make the pages of internet websites visible. Such software can also operate on smaller devices, such as a laptop, often used by those who work on the move. In this particular case we use the term ‘web server’. Among the most well-known of these are Apache, Nginx and IIS, which may be installed on any device and are able to host more than one website.
Their main job is the storage of files on a web site, which are subsequently made available to clients who visit the site. Communication between server and client is based on the HTTP/HTTPS protocol (the second option provides greater guarantees regarding data security).
This role can also involve other services, such as the management of emails, FTP and NFS, which make files available on the web. There are in fact many different types of web server. These are some of the most important ones:
- DNS servers, which are used to memorise dominion names. DNS is in fact an acronym of Domain Name Server;
- Database servers. The main purpose of this type of server, as is apparent from their name, is to make available data stored in a database. This is fundamental for the management of websites;
- File server, which are used to store all the files shared with the client. This kind of web server is widely used in companies and allows all stored data to be made accessible.
There are also proxy servers, an essential resource for ensuring anonymity and filtering connections.
Obviously, the term server is also applicable to supercomputers as mentioned above. In reality these are a combination of computers, or to be more precise, of Data Centres formed of various servers positioned together in rack units.
These devices are not particularly exceptional in terms of performance. Everything depends, in fact, on what needs to be managed and above all on the size of the workload. In some areas, they can be less powerful than a good quality workstation. They are undoubtedly superior when it comes to reliability, considering that they guarantee an optimal service 24 hours a day, 365 days a year.
Distinctive features of computer servers
It is now clear that, when the term server is used, it refers to a role or function rather than a physical object. In reality, it can be used to define any IT system, whether hardware or software, able to provide the user with information.
The oft cited term client however, refers to an entity which uses the services that the servers provide. The client could also be a software (eg a browser) or a piece of hardware (such as the PC or smartphone).
If we return to the theme of the server, it is important to remember that computers built to offer a high level of performance while managing intense workloads, have specific features. Here are the main ones:
- Numerous CPUs and/or Cores
- Large RAM memory capacity
- Hard Disks or groups of Hard Disks which have large memory capacity and are very fast;
- Redundant power supply (presence of two or more power sources);
- Redundant network motherboards;
- Extremely efficient cooling systems (a considerable amount of heat is produced);
- Fibre optic connection.
If the workload is not excessive and the performance required is within normal levels, even a simple PC can be used as a server.
Translated by Joanne Beckwith