What does a Model: WDBABY0000NBK-NESN do?

hi im new to all this good IT stuff i have just got a wd media player

and it is wired to our adsl2 modem then wired to our TV via a LONG ethernet cable

and i would like to get reception in other rooms wirlessly

what is and what does a WDBABY0000NBK-NESN  do

 i have read the ad but i dont under stand just what it does

thanks in advance for an explanation

Look at the example on page 4

http://www.wdc.com/wdproducts/library/UM/ENG/4779-705041.pdf

Thanks for the reply i did manage to get some good info of the net

what i need to know now before i go and by one is CAN I ADD EXTRA ROOMS (outlets) to the primary receiver ??

You would have get other unit as stated in the documentation

i see 

 would there be any problems with cross /mix signals with 2 units plugged in the the same ADSL Thomson gateway

does it mater witch phase you are connected to as the netgate ones seam to have problems with that

can you just change the wiring around in the house hold  outlet if you don’t get a signal ?