For many years, TVs were 60Hz, which means the image refreshes 60 times per second. If you took a photo of a 60Hz TV with a camera that had a shutter speed set to 1/60 of a second or faster, you would see a black bar across the TV image. The camera in this case is catching the image refresh mid-stream. During fast motion during a TV show, 60Hz would cause a lag of the image because the action is catching the refresh mid-stream too. Then came 120hz and now 240Hz TVs that artificLly add extra duplicate video frames. These duplicate frames eliminate the lag during fast motion, but in the case of 240Hz TVs, they make the image look like everything was shot on a video camera. Not too bad for stuff shot on video, but to me, horrible on film based sources like feature movies. I do not want Star Wars looking like it was shot on video. I own two 120Hz LCDs and two Plasmas. The 120Hz TVs have acceptable images and actually look quite stunning on film sources. I spend a lot of time watching a 240Hz LED which has the horrible SOE. The Plasma has the best image for film content. One other issue with LCD and LED sets is the pixel refresh rate, stated in Milliseconds. This is the time it takes an individual pixel to changes from Gogol white to black, and most LCD and LEDs are typically rated at 5ms. Because Plasma TVs have a different way of image display, they have pixel refresh rates that are basically 1ms. Slow pixel refresh rates give another bad effect where you have pixel lag. If you look close at some LCD/LED TVs, you will see pixel blurring, which is the pixels trying to refresh but the image is changing before the pixel can refresh. Plasma sets do not have this. In the past, Plasmas got a bad rate because of image burn-in, but today's Plasmas do not have this. They also have what is called Pixel Orbiter, that moves all of the Pixels automatically every so often so no burn-in happens. The current drawback of Plasmas is that they aren't as flat as LED.