There are lots of different types of electronic screens on the market today, and it is really hard to figure out what they are all about.  Here is a small explanation of them.

CRT
Cathode Ray Tube technology has been used since the very first TVs.  It basically uses three tubes beside each other (red, blue, green), to create an image that is ‘fired’ onto a glass screen.  The cathode or ‘gun’ fires an invisible electron beam at coloured phosphors that are on the glass screen.  These phosphors glow in their respective colour (red, blue, green) to produce the picture.  These displays are inexpensive, very reliable, and have the best colour reproduction.  The problem is that they are big and heavy, and consume a large amount of electricity.

LCD
Liquid Crystal Displays first appeared in calculators in the 1970s, and has been widely used in every laptop computer ever made.  This amazingly versatile display is a matrix of thin transistors that supply power to liquid crystal filled cells that are sandwiched between two sheets of glass.  A group of red, green and blue cells make up one pixel of the image.  A strong light mounted behind the screen illuminates the various cells, making the final image.  These screens can be only a few inches deep, and use a lot less power than a CRT screen.  The downside is that LCD is not very good at reproducing blacks, and the viewing angle can be fairly narrow.

PLASMA
Glass Plasma TVs usually range from 3 to 6 inches deep, and can be as large as 103″ or more!  Each pixel in a plasma display consists of three glass-filled cells coated with red, green or blue phosphors.  By running various amounts of voltage through them, they produce coloured light.  The are used mostly because of their wide viewing angle, and large screen size.  They are still very expensive and are subject to burn-in.

DLP
Digital Light Processing offers a high quality and less expensive alternative, mostly used in front projectors.  The screen is packed with nearly a million ‘micro mirrors’ that reflect light from a lamp onto the screen.  In most projectors, there is a chip that controls each colour individually (red, green blue).  It produces deeper, more realistic shadows a blacks than any other technology… and there is no danger of burn-in.

LCoS
The least familiar technology is Liquid Crystal on Silicon, and it is a close cousin to LCD technology.  The difference is that is can provide a higher resolution, by mounting the crystals to a silicon chip instead of between glass.   Even though these screen are expensive right now, their high resolution is a big plus.  Keep an eye on this one!