If you are in the market to buy a 40 inch LED TV it helps to know what you should be looking for. LED lighting is the latest buzz in LCD TV technology. Also known as LCD backlit televisions, LED TVs are not the same as a standard LCD TV. When you buy a 40 inch LED TV it uses a light emitting diode to back light the screen instead of a compact fluorescent bulb, which is what is used on standard LCD televisions. The advantage to the LED TVs are plentiful, including lower energy consumption, longer product life and best of all better picture. When selecting a 40 inch LED TV the first thing you want to look at is whether it is backlit, or edge-lit. Backlit sets are a little larger in size, but they display a full array of LED lights across the back panel of your television screen. This provides more a more uniform picture. Edge-lit LED screens have smaller lights on all four sides of the screen so the TV itself can have a slimmer design. Edge-lit TVs are not as uniform; blacks may appear gray on the edges of the screen and whites may appear brighter at the screens edge. If you decide to go with a backlit set over an edge-lit set you need to make sure it has a feature called local dimming. Local dimming will independently dim the backlight when areas of the screen get brighter, or darker. This helps improve the contrast ratio and improves the picture overall making it crisper and more realistic. It is also important to select a 40 inch LED TV that has a high refresh rate. At minimum you want to choose a model that has a refresh rate of 240 Hz. You should also choose a set with a refresh rate time of at least 3 MS. This will prevent you from seeing any ghosting of the image, or lag when you are playing games, or watching action scenes on your 40 inch LED TV.