Discussing remote display protocols
As we mentioned previously, there are different virtualization solutions, so it's only normal that there are different methods to access virtual machines. If you take a look at the history of virtual machines, we had a number of different display protocols taking care of this particular problem. So, let's discuss this history a bit.
Remote display protocols history
There will be people disputing this premise, but remote protocols started as text-only protocols. Whichever way you look at it, serial, text-mode terminals were here before we had X Windows or anything remotely resembling a GUI in the Microsoft, Apple, and UNIX-based worlds. Also, you can't dispute the fact that the telnet and rlogin protocols are also used to access remote display. It just so happens that the remote display that we're accessing by using telnet and rlogin is a text-based display. By extension, the same thing applies to SSH. And serial terminals...