How does layering hair and thinning hair work?

My hair is very thick, and i am trying to grow it out, not too long though..


People tell me that i need to get it thinned and layered..





I am not sure what these do, and how they work.. ThxHow does layering hair and thinning hair work?
Layering = taking a flat, thin section of hair , pulling it up or out %26amp; cutting it straight across. Results in shorter hair at the top %26amp; strands gradually getting longer.





Thinning = using of special scissors which cut intervals of short hair. Can be done to thin out hair or create volume/spikes.





Photos for your reference:


example of face framing layers: http://matrix.com/find_your_hair_style/l鈥?/a>





curly hair cut w/ layers to create definition/shape:http://matrix.com/find_your_hair_style/m鈥?/a>





layered ends to thin out bottom of bob:http://matrix.com/find_your_hair_style/m鈥?/a>





use of texturizing %26amp; layers to make waves manageable:http://matrix.com/find_your_hair_style/s鈥?/a>