A dedicated server is essentially an entire server in a data centre. You can opt for a managed or unmanaged service.
With a managed service, you’ll have someone running your hosting for you, ensuring things are patched, running smoothly and kept up to date and secure. With an unmanaged service, you’re left to sort these things out on your own.
Dedicated servers are required for websites with a great deal of traffic, very heavy web applications or incredibly large websites receiving 10,000’s of sessions a month.
Unmanaged dedicated servers start at around £200 per month, whereas for a managed dedicated server you can expect to pay from £400 to thousands per month.
Whilst they offer a large amount resources and flexibility, they’re also costly and can require a great deal of maintenance.