1: Dark reaction or calvin cycle
2: Light dependent reaction
The main difference between these reactions is their dependency on light. Calvin cycle occurs without needing light,where as the light depending reaction, as the name suggests, cannot occur when the light is not available.
Calvin cycle use carbon dioxide to make sugar and provide energy and the hydrogen ions to the plants, where as the light dependent reaction or photosynthesis use light to make ATP and NADPH2 for the sugar making process of the calvin cycle.