Page 1 of Macrovision what is it

Could someone please give me a "idiots guide" to what macrovision is .

Macrovision is a mechanism of stopping video signals being recorded. It fiddles with the signal that occurs when the picture scanning returns to the top of the screen from the bottom between each displayed frame. TV`s aren`t affected by this interference but it screw up VCR`s and some home cinema systems. There are cables and boxes you can buy to correct the interference if you can`t find a way to disable it from the video source.