Chyron is a company who's products include tools for
character generation,
graphics,
editing, compositing, and other such things for
video and
broadcasting.
The hardware and software that they make are used for
special effects
and
video editing.
Some examples of the things that they do is overlaying the score box
on a live sports broadcast or combining two video feeds in different
parts of the screen - this technique is often used in game shows to show
the face of the contestant and the board at the same time.
As a specialized piece of hardware, it needs someone who is familiar with
its workings to use it, thus the title "Chyron Operator".