The world space is the space where all objects are located in your game.  You can have objects, lights and cameras in world space. OpenGL doesn’t really care about world space. This is because there is no difference between transforming the world or the camera. For example translating the camera with the vector t is the same as translating the world with the vector -t. OpenGL uses therefore a single matrix called ModelView that holds the transformation from world space to eye space.

This matrix can be manipulated after setting the matrix mode to ModelView with this line of code:

glMatrixMode(GL_MODELVIEW);

Description of the different 3D spaces:
http://vesta.astro.amu.edu.pl/Library/Linux/LinFocus/May1998/article6.html
http://pages.cs.wisc.edu/~psilord/docs/local_axis.html