What are servers?

A server is a computer that receives requests over a network, performs requested functions and sends back responses. The term can also refer to the software package that provides the service.

Any computer can act as a server, but many manufacturers offer dedicated systems designed for server roles. Such a system might have more memory and storage than a regular desktop PC, so it can process requests from many clients at once. It may use technologies such as error-correcting RAM and RAID storage, to reduce the risk of a hardware failure leading to downtime or data loss. A second, redundant power supply may be built in too.

Server systems come in two main formats: a tower server looks like a desktop PC but is larger, so it can accommodate more expansion cards and storage. Rack servers conversely use a compact format that’s designed to be mounted in a cabinet, saving space at the expense of expandability.

What can servers do?

There are many types of server. A medium-sized company might operate email and storage servers, along with a database server that allows staff to find and cross-reference customer data as needed. Businesses with more advanced needs might run a CRM server, or some other type of application server that works in partnership with a front-end client application, allowing users to collect, manage and analyse data.

Servers also underpin the network itself. DHCP and DNS servers handle addressing requests, enabling computers to connect to one another, either internally or over the internet, while web servers receive HTTP requests, and send HTML pages in response.

Can a server provide multiple services at once?

There’s no technical reason why a single server can’t provide any number of services, but resource management becomes crucial when multiple services are sharing memory, processor power, storage and network bandwidth. Get it wrong and slowdowns or crashes are inevitable.

If multiple services are all running under one operating system, there’s also a risk that their operations could interfere with one another – and a single software failure could take down all the services at once. Security is a concern too, as a vulnerability in one service could allow an attacker to gain access to all the software or data on that machine.

For these reasons, when running multiple services on a single physical server, it’s common to use virtualisation to run each in its own isolated environment. This significantly increases the resource requirements, but it provides better stability and security.

What is the future of servers?

The past 20 years have seen many companies decommission their servers and switch to cloud computing services. This can bring considerable savings – and additional flexibility, as cloud resources can easily be expanded and reduced to follow demand.

However, accessing cloud services is much slower than using a local network connection, and introduces concerns over security and data sovereignty. Many companies now adopt a “hybrid cloud” approach, using both hosted services and in-house servers for the roles they’re best suited to – so while server hardware isn’t likely to die out, it’s expected to become more niche and specialised.

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If so, you might want to check out others we’ve published in our hardware section, including What is Intel vPro?, What are virtual machines? and What is Wi-Fi 7?