I've seen tvs that are either led or lcd. then there are tvs that say they are led lcd. what's the difference?

The correct description is a actually "LED / LCD". When LED back-lights for LCD televisions were developed to replace the fluorescent tubes that were in use, the TV manufacturers and retailers saw an opportunity for a big marketing "scam". The new LCD televisions with LED back-lights were simply sold as "LED televisions", without mentioning the fact that the actual screen was still LCD, the same as it had always been. This has caused a lot of confusion with the general public, many of whom think they are buying a totally brand new technology. Whilst the newer LCD televisions with LED back-lights are thinner, lighter and use less power than these fitted with fluorescent tube back-lights, the LED technology is still new. Many of the new LCD / LED televisions suffer from poor back-light quality. This hasn't affected sales though, so the manufacturers and retailers are doing very nicely. There are two LED back-light types - edge lit and full array. Edge lit has the LEDs arranged around the bezel of the the TV. Full array has them behind the whole of the screen. Neither one is better than the other. The only true LED televisions you can buy in Britain (one from Sony and one from LG) are small (11" and 15" screens respectively) and expensive for their size (around £1,000 each).