Liquid Crystal Displays or as they are more commonly know LCD's are made up of many different layers that are pressed together. Liquid Crystal, onto its self is a special type of fluid that has cylinder looking crystals that can alter light as it passes through it. This fluid is "pressed" between Aligning layers (which have fine grooves) and the crystals basically line up in these grooves, when pressed together. The next layer to be added would be a polarized filter. It is used to allow or block a polarized light from shining through, depending on where voltage is applied.

Samsung SyncMaster 170T LCD Display