Specifically the past two decades. During this time, there was a revolution in the display industry, and this came in the form of LCD displays and plasma displays. The formerly comprised LCD panels, which were flat, and the latter were much like a traditional cathode ray tube monitor or CRT Technology. The most significant difference between the two was that LCDs did not use vacuum tubes used in CRT Technology.
LCD technology in televisions went through several advancements during this period. First off, displays became smaller and lighter. Next, they became more energy-efficient, which led to an increase in the number of units used at a time. Finally, they began to incorporate backlighting systems into their screens. This would allow the screen to be dimmed and brightened, which was something that CRT Technology was never able to accomplish. As new LCD units hit the market, these advancements were quickly made available, and many manufacturers quickly began using these new features in their CRT display units.
To know more about the progression of TV technologies, check this infographic by Irwin’s Megastore.