When you buy hosting for your website, a server in a datacentre will run your website.

I worked in such a datacentre for many years. There were 300 servers and a lot of other hardware.

We needed to write a lot of software to monitor these servers and to manage the information about them.

There was all the hardware and software you can imagine: databases, application servers, front-end servers, routers, load balancers, firewalls, mail servers, authorization servers and so on.