The chemical equation for photosynthesis can be written as:
6 CO2 + 6 H2O + radiant energy -> C6H12O6 + 6 O2
In this reaction, green plants (containing chlorophyll) consume carbon dioxide and water and, in presence of sunlight, produce glucose and oxygen. Thus reaction is of great importance for a number of reasons. This reaction makes plants the primary producers, organisms that generate food for others. A large number of living organisms including human beings are dependent on plants for their food requirements. Plants also produce oxygen, necessary for cellular respiration, through the process of photosynthesis. Also, this process is also responsible for consumption of atmospheric carbon dioxide and thus maintains a balance of carbon dioxide in our atmosphere and keeps the greenhouse effect in check.
Hope this helps.