Shot/reverse shot
Shot/reverse shot is where one character is looking at another character. We see the first person talking to the other and we see on of the faces and the back off the other persons head and that is called shot when one character is talking to the screen. Then the cameras turn and you see the other characters face and the back of the head of the character who was talking first which is called reverse shot.

Here is an example were the king is talking to the messenger:
http://www.youtube.com/watch?v=bnH6L1qcREQ