What does "platen" mean?

Platen: (a) The part of a printing press which presses the paper against the type and by which the impression is made. (b) Hence, an analogous part of a typewriter, on which the paper rests to receive an impression. (c) The movable table of a machine tool, as a planer, on which the work is fastened, and presented to the action of the tool; -- also called table.