Whats the purpose of ethernet adaptor like this one?

http://www.amazon.co.uk/gp/product/B004INVKP4/ref=nosim/?tag=hotukdeals-21
what exactly are these?
Answer #1
http://computer.howstuffworks.com/power-network.htm
Answer #2
im still confused honestly
Answer #3
So am I.
About a great many things.
Would you please let us know, what it is in particular that confuses you so?
Answer #4
try this youtube vid http://www.youtube.com/watch?v=tU1_IEUKQjA
~lionden~
Answer #5
like what it iactually is
Answer #6
They are powerline adapter which are ment to use the powersockets in your homes wall to transfer the signal. You plug one into your router and one into your device. Useful if you have an old house with very thick walls or a big house.