What are these two things on the side of a stage? Currently watching a lot of presidential videos (you know why) and I noticed there are these two black things on the side of the stage:

What are they and what are their purpose?
I believe they are teleprompters. They contain the text of the speech the person at the podium is reading. In this case, the camera is very far away, so they can't be projected onto a half-mirror in front of the camera as is normally done.

Here is a close-up of one used by President Obama.