TFT means "thin film transistor". By itself, it does nothing. But when combined with an Liquid Crystal Disply (LCD), you have a powerful display.
The LCD by itself works fine, but so did electronics before the transistor. Then the transistor came along. The most powerful thing about transistors is that they allow us to control almost everything we need with electronics. And they are incredibly reliable. An LCD requires a voltage to make a dot appear on the screen. With TFT, the electrical components of the LCD are smaller, much more reliable, and more controllable.
As the TFT becomes more refined and utilized, you can expect to see the size, weight, and energy consumption of LCD displays to go down while the clarity and resolution to go up.
For more information of LCD’s, I would suggest visiting a great description
that the Physics Van posted.
(published on 10/22/2007)