television vs telecasting

television and telecasting both are nouns.

Word	Noun	Adjective	Verb	Adverb
television	Yes	No	No	No
telecasting	Yes	No	No	No

As nouns, television and telecasting are synonyms defined as:

television and telecasting: broadcasting visual images of stationary or moving objects

Other synonyms of television include TV, video.

television (noun)	telecasting (noun)
a telecommunication system that transmits images of objects (stationary or moving) between distant points	broadcasting visual images of stationary or moving objects
an electronic device that receives television signals and displays them on a screen
broadcasting visual images of stationary or moving objects