Direct View (Tube) Direct View screens use a glass Cathode Ray Tube (CRT) to produce the image you see on the screen. Most portable screens with this type of technology will only have a screen size up to 9 inches (diagonal screen size). Direct View monitors are available with either curved or flat screens.
Flat Panel or LCD (Liquid Crystal Displays) use liquid crystals as optical shutters, which control the amount of light passing through the thin display screen, creating vivid, life-like colors. These monitors are incredibly thinner than CRT models, therefore allowing them to be placed in headrests and overhead displays. LCD monitors can have a depth of just 1 to 3 inches.