The cathode ray tube or CRT, invented by Karl Ferdinand Braun, is the display device that was traditionally used in most computer displays, video monitors, televisions and oscilloscopes. The CRT developed from Philo Farnsworth's work was used in all television sets until the late 20th century and the advent of plasma screens, LCDs, DLP displays, and other technologies. As a result of this technology, television continues to be referred to as "The Tube" well into the 21st century, even when referring to non-CRT sets. LED giant screens and CRT monitors are totally different, both for functioning principle and type of application.