Most websites are hosted on computers alongside many others. That means sharing the computer’s resources – space, RAM, bandwidth – with other customers. Most hosting companies give their customers plenty of space for their database and website pages, but when neighbouring websites are busy they can hog the bandwidth and processor and have bad effects on your own services. Pages start loading slowly for your visitors and your back-office management operations become sluggish or fail.
Another disadvantage is that you can’t change the server settings to work best for your own website because they might not work for others. Neighbouring websites also increase your security risks: if they are hacked or infected by a virus the consequences can spread to you. For the same reason, hosting companies are reluctant to let you install unusual software – in case it poses a threat. Lastly, if your neighbours are up to no good it can detrimentally affect your SEO – because you probably share an IP address.
Who would want a shared web hosting account?
Most people. Shared web hosting is cheaper and if the hosting company is any good they will still deliver good performance (you can compare them here: https://www.names.co.uk/web-hosting). The obvious alternative is to have a server to yourself. As you would expect that means paying more, but sometimes it is worth it.
Reasons for a dedicated server
If your website needs a huge database – because you have thousands of customers and products – the space, bandwidth and processing power of a dedicated server may be essential.
If your website is controversial and therefore likely to attract hackers, or if it stores very sensitive information (such as mental health data), full control over the server’s security could be the deciding factor. This assumes you have sufficient security expertise to protect it – but security administration can also be outsourced.
If you are a developer and need to develop or host unusual software on the server, then a dedicated package will give you freedom to configure the server whatever way you need.
A compromise between shared and dedicated hosting is a VPS account. This means your website is hosted in its own secure partition with guaranteed resources and better protection from other websites. You can also configure many of the settings the way you want too, so it is called a “virtual private server”.