Fortunately, all the people I have come across so far have simply called it... "Computer".
I do remember from my primary school days - almost 3 decades now -, the computer class teacher first taught us the "computer" system that we see externally is made up of
1. The "CPU" - 'Central Processing Unit', - which is usually drawn as the desktop-box (and in later years they started drawing the tower shape) to label it as the "CPU" on the white board marker.
2. The Monitor, and
3. The Keyboard
Speaking of computer class, I can still remember the smell emanating from the heat of running monitors and the "CPUs" in the AC room...
Was using LOGO those days on Hercules monitors.