And loads of other vauge crap, that is useless to me, because it won't go into detail.
I've been a bit frustrated by that missing next step. However, I'm rather sure that it involves the actual math behind this. I know I don't want to work that hard at it and I'm guessing you won't either.
I think (emphasize *think* - we need cavediver and others to drop in here)that the "string" are objects in the mathematics and by adjusting one or more parameters (vibration modes) you get results consistent with the properties of individual types of particles. However, I don't have the math to understand that level of detail or derive the results myself.
String theory isn't *the* answer yet anyway. It's got some interesting mathematical behaviour but it hasn't been tested yet. Until experimentation catchs up to theory it is just interesting.