Do we explain a graph in results or discussion? My project is to characterize a behavior and I have several graphs for the same, that I have put in my results section. Should I explain the graph in the results section or the discussion section of my project report?

For example, say a graph has a groupwise comparison, do I have to explain the inference of the difference in the curves in results or discussion? If I have to do it in the discussion section, wouldn't it be difficult since to explain such a thing I'd have to repeat the graphs there too?
It may depend on your field or specific journal, but typically:
In the results section, describe the pattern quantitatively, with perhaps just a mechanistic matter-of-fact interpretation. 
In the discussion section, revisit the pattern but interpret qualitatively within the scope of your research question, tying it into your overall narrative. 

For publications with severe space limitations (e.g. Science, Nature), jump straight to qualitative interpretation and present quantitative results in the figure caption.