Are the terms screen and the monitor in computer graphics used interchangeably? I was looking at this Wikipedia article about the image plane or the screen space


  https://en.wikipedia.org/wiki/Image_plane


and at a certain point there's


  A rectangular region of this plane, called the viewing window or viewport, maps to the monitor.


Here, by "plane" they are (I think) referring to the image plane (or screen space); but I'm wondering now what do they mean here by monitor. 

Is the monitor the same thing as the screen? Is the screen the plane in the monitor, but people in computer graphics usually say only monitor to refer to the screen?

Or, maybe first of all, what is intended by screen and monitor in computer graphics?
The terms screen, monitor, and display are used more or less interchangeably to refer to the real-world physical device that shows the image you're looking at. (They're not 100% interchangeable: monitor means a discrete display device such as you'd use with a desktop PC. However, a built-in display such as the one in a laptop, tablet, or phone is never called a monitor.)

The image plane means the abstract geometric plane that identifies the surface of the display, but extends infinitely in all directions, i.e. isn't bounded by the edges of the display. The viewport or viewing window is the rectangle within this plane that identifies the edges of the display (or more generally, the edges of the image you're rendering, in case your app is running in a window and not fullscreen).

The term screen might also be used more colloquially to mean various other things, such as: various coordinate systems on the image plane ("screen space"), the viewport or view frustum ("the object is off-screen"), the back buffer ("render it to the screen"), and probably more.