Every website, no matter how simple, is made up of files: HTML documents, images, stylesheets, and code. Those files have to live somewhere that is switched on and connected to the internet at all times. That is the function a web hosting service provides.
What a server actually is
A server is a computer, similar in principle to the one on a desk or in a pocket, but built and configured to stay running continuously and to respond to requests from other computers. A hosting provider owns and maintains large numbers of these machines, arranged in data centres with reliable power, cooling, and internet connections. Where those data centres are can affect both speed and privacy, as explained in Where Is Your Data Actually Stored? Server Location and Data Sovereignty.
What happens when someone visits a site
When a visitor types a web address into their browser, several things happen in quick succession:
- The browser looks up which server holds that website's files.
- The browser sends a request to that server asking for the relevant page.
- The server locates the requested files and sends them back.
- The browser assembles and displays the page.
This exchange typically takes a fraction of a second, but it depends entirely on the server being available and responsive. If the server is offline, slow, or overloaded, your visitor experiences that as the website being broken. How reliably a provider keeps its servers online is usually expressed as an uptime figure, covered in Uptime Guarantees: Why 99% and 99.9% Aren't Basically the Same.
Why most people don't run their own server
It is technically possible to run a website from a computer at home or in an office. In practice, almost nobody does, for a combination of reasons:
- Reliability. A home internet connection and power supply are not built for continuous uptime.
- Security. Servers require ongoing maintenance to guard against unauthorised access.
- Cost and expertise. Commercial hosting providers achieve efficiencies of scale that are difficult to replicate individually.
A hosting provider takes on these responsibilities as its core business, which is why hosting is normally purchased as a service rather than built independently.
Who manages what
A hosting arrangement divides responsibility between two parties. The provider is typically responsible for the physical hardware, the data centre environment, network connectivity, and the underlying server software. You are typically responsible for the content, structure, and configuration of the site itself, though the exact split varies by plan type and provider.
When hosting becomes necessary
Hosting is required from the moment your website needs to be reachable by anyone other than you. A site being built and tested only on a local computer does not yet need hosting; a site intended to be visited by the public does. This is the starting point for every other decision covered in this series — including Web Hosting vs. Managing a Server Yourself: Why Most Sites Don't Need the Extra Work and A Practical Checklist for Comparing Hosting Providers Side by Side. Once you know you need hosting, you can start comparing web hosts.
*This article was drafted with the help of AI. It was fact-checked and edited by a real person.