Photosynthesis is a process which uses sunlight energy to synthesize food in the form of glucose. The process takes place in the chloroplast in two stages: light-dependent reactions and light-independent reactions.
The light-independent reaction produces to convert the carbon dioxide from the atmosphere to glucose through the Calvin cycle. The carbon gets fixed and reduced form+4 state to +1 state.
Respiration is the process which oxidizes the glucose molecule to produce energy in the form of ATP molecules. This ATP is utilized by the cell to perform various functions.