How the pictures on a television are made depends on what kind of technology it uses, but they all take advantage of the human brain's capacity to assemble a coherent scene out of tiny colored dots called pixels. The three most common technologies used to transmit these pixels are the cathode ray tube, liquid crystal display and plasma display, according to HowStuffWorks.
The cathode ray tube, or CRT, is the oldest television technology. It involves a heated filament inside the vacuum of a glass tube. The filament emits electrons, which are focused and accelerated so they hit the screen at the end of the tube. Steering coils inside the television create a magnetic field that moves the electrons horizontally or vertically. The screen is coated with different phosphors that glow with color when struck by the electrons.
Liquid crystal displays, or LCDs, and plasma screens offer lighter, more energy-efficient means of transmitting television by eliminating the need for the bulky cathode tube. LCDs rely on liquid crystals, which modulate the light behind them in various ways when an electric current is applied. Plasma screens, on the other hand, work by illuminating many tiny fluorescent lights in three different colors to create a meaningful image.