It turns out that until the late 1990s, most of IT applications were deployed to bare metal machines. This means that you used some sort of server hardware and installed an operating system on it, and on top of that, your applications were installed.
But virtual machines are quite old. In fact, by the early 1960s, IBM was capable of running virtual machines on their mainframes, but it took decades until virtual machines experienced huge market adoption. Most likely, the reason for this was that consumer grade hardware was not powerful enough to run virtual systems efficiently. However, as we all know, this has changed dramatically.
Nowadays, a modern server can run hundreds of virtual machines ...
