Transluscency vs. Subsurface Scattering

Hi there, i am playing around little rendering translucent materials. I am quit new to this and not realy get the main concepts in CG. I played around with the Translucency shader in cycles and found it quite nice. I read about that SSS will be included into cycles in future.
But what exactly will be the difference… what is the limitation of Translucency? And what are the different concepts in faking SSS apart only using the Translucency shader?

translucency works well for something thin like an ear which a lot of light will pass through, but other parts of the head would be virtually unaffected, unless you put a lamp inside the head.

see definition here

translucent is one material which lets some light go throught
but does not do samething then SSS


Translucency allows light to scatter through an object from only one direction. SSS allows for light to enter a surface with some passing through, and some reflecting back out through the same side it entered into. There are plenty of examples of good backscattering materials in Cycles that can approximate skin, but without dedicated code there isn’t a way to do forward scattering (light entering, bouncing through different depths like skin, muscle, fatty tissues, etc. and picking up new colors) without faking it with compositing.