A Telestrator (also known as Video Marker) is a device that allows the announcer or operator on a computing platform to draw a freehand sketch over a paused or still video image. This device is often used in weather broadcasts and sports. Leonard Reiffel, an American physicist, author, and educator is recognized as the inventor of Telestrator in the year 1950. This technique is predominantly used in televised sporting events.
With the help of this technology, the announcer can mark significant observations on a paused video of a live action taking place in the field. They can draw the path of the action with graphic objects such as lines, arrows or any other shapes using different colors. This technique is often used in the field of education, military presentation, sports, etc., At present, Telestrators are being widely operated in broadcasts of all major sports.