A teleprompter (also known as an autocue)'s a display device that prompts the person speaking with an electronic visual text of a speech or script. Using a teleprompter's similar to the practice of using cue cards. The screen's in front of the lens of the camera, and the words on the screen are reflected to the eyes of the speaker using a two-way mirror. (Note that this's only true in principle — when the space between the lens and the mirror's covered in a shroud, an ordinary glass pane… (More on Teleprompter)