What are those glass things that stand at an angle in front of speakers?

Question

Watching speakers like the presidential candidates and others, I notice two rectangular glass things propped up in front of them. What are they?

Answer 1

Those are teleprompters. Like news casters they are reading the words as they say them.

Answer 2

As the others say, it is a reflector for the projection of a scrolling display of the speech, speech notes, or outline.  When newscasters use one, it is mounted on the camera with the lens looking though the glass so the caster is always looking into the camera.  The cameras at conventions are too far away for this to work.

Answer 3

It is a fancy teleprompter.  A teleprompter is a device like a television that a speaker can look at to know what he/she has to say.  The words the speaker needs to say are written and scrolling on the teleprompter.  The sheet of glass in front of the speaker is showing a reflection of the speech/words they need to say.  It is visible to only the speaker.  Pretty neat, eh?