Solution:
1. MODEM or CODEC have been tossed to emphasize this fact. What
is meaning of this line?
Answer: In order to overcome the issue the concept of MODEM or CODEC applied or used.
2. what is CRT?
Answer: Cathode Ray Tube (CRT). Previous TV standard.
3. what is the meaning of luminosity?
Answer: Luminocity means the presence of white light.