While cultural anthropologists have engaged in numerous philosophical and theoretical debates over the definition of "culture", the following is a reasonable distillation.
Culture - Learned and transmitted behavioral and technological information conducive to a groups adaptation to, and survival in, a given environmental setting.
Thus, comparatively small (or notably extended) groups share some degree of commonly transmitted knowledge. This does not necessarily imply higher levels of social organization and structure.
Civilization, on the other hand, incorporates (as noted by Searcher) a number of additional elements. Again, definitions can have some degree of variability. The following reference may provide some insight:
Reading that website makes my feeling that it is nothing but bickering about the exact meaning of some word only stronger.