The next set of reactions are termed the dark reactions, or light independant reactions, or the Calvin Benson cycle..  This is because no light is needed for these reactions to happen directly.  You should notice however that ATP and NADPH are used here in this set of reactions, and these are directly from the photosystems.  This makes the two sets of reactions dependant upon each other, as neither could happen without the other.  The light reactions create ATP and NADPH, while the dark reactions create ADP, NADP+, and G3P.  

 

This complicated set of reactions really has a few important concepts to understand.  It is here you see why carbon dioxide is needed by plants.  Without it you could not complete photosynthesis, as can be seen here.  Also we touched on ATP and NADPH being needed also, and their relationship with the light reactions.  At the bottom of the cycle you see G3P.  This molecule is can then go straight into glycolysis to help produce more ATP.  Eventually the cycle continues to help replenish the molecules that were used up in the previous cycle.