LCD: Liquid Crystal Displays use liquid crystals to produce images. Each crystal acts like a shutter, either allowing light to pass through or blocking the light. The screen is illuminated behind the panel by a fluorescent backlight. LCD screens are typically brighter, making them good choices for viewing in rooms with lots of light. These models are energy-efficient and lightweight, allowing easy placement on walls, etc.
Plasma: This type of screen consists of cells charged by precise electrical voltages to create a picture. By varying the voltage and intensity of the electrical charge, the proper combination of red, green and blue light is produced in each pixel to combine into a bright, colorful composite image. Plasma TVs are self-illuminating and don't require a backlight. Plasmas are known for producing deeper black levels, which make them a smart choice if you do a lot of viewing with your room's lights dimmed or darkened. Plasma TVs have an excellent viewing angle, contrast ratio and black levels, and faster response time.
LED: High-performance LCD TVs that use energy-efficient LED blacklight. It can either use Edge Lighting, where a series of blacklights are placed along the outside edges of the screen, or Full- Array backlighting, used by more advanced models, which places several rows of LED backlights behind the entire surface of the screen that can be turned on or off, allowing local dimming. Local dimming provides more control of the brightness and darkness.
Ultra HDTV: 4K Ultra HD LED screen that has twice the horizontal and vertical resolution of the 1080p HDTV format, with four times as many pixels overall. The pixel count for 4K Ultra HD is 3840 x 2160, compared to 1080p HD at 1920 x 1080. The high pixel count sharpens the picture drastically making it more realistic. It also allows you to experience a seamless picture at a closer viewing distance. With 4K you are able to upscale your existing content (internal or external), however upscaling capabilities will vary in quality across models and brands.