More technology self-tutoring: the tutor explains the idea of a virtual machine.
An entity that is accessible via keyboard and screen, like a desktop, and may function, to the user, like a standalone computer. However, the virtual machine resides in a server or computer that may host many others as well.
In a simple case, each employee might use her/his own separate VM at work, but in fact all of the VMs might reside on a single server. (In reality there would likely be at least two servers for back-up purposes.) Yet, each employee experiences their own PC.
On the client side, the actual deployment of the virtual machines might be accomplished via network connectivity and login credentials.
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.