Photoshop "Extended"

basically i would like to know the difference between photoshop (cs3) and photoshop (cs3) extended.

is the extended free or meant to be free? because all the downloads i seen on even on legit sites.

also is the extended got less stuff e.g. effects

ty in advance :P

extended is an expansion i think
it will work only with cs3. idk i got cs3 extended and there are nothging less effects everything is there.

and free dld? i dont get it legit sites dont allow free downloads