What's the difference between layers and thinning out?

I'm getting my hair cut on Saturday, and I have really thick hair. It's all too much, and I'm interested in getting it layered. But I've heard people using the term 'thinning out' and I don't know if this is the same as layering. If it isn't, would you recommend it?What's the difference between layers and thinning out?
Layering is just that...layers. Thinning is going into the layers to thin out the layers. This is perfect for really thick hair so that it's not so bushy. Thinning shears are used instead of scissors.What's the difference between layers and thinning out?
wow. so i'm not the only one wid that prob. hmm...i think 'thining out' has got somethin 2 do with straitening but layers is basically to chop hair in different steps to make your hair look less dense...