What is the difference between Samsung Gingerbread and Touchwiz?

I'm thinking of getting the Samsung Nexus S or the new Samsung Galaxy S2, but the Nexus S keeps referring to "Gingerbread" and the SGS2 refers to Touchwiz. I'm new to all this Android Language so I'm still in the learning stages.. Any answers would be of help as a first time Android user. thx.|||http://samsunggalaxys2review.org/forum/