The most accepted theory of evolution by Oparin-Haldane hypothesized that the early cells, evolved during the highly reduced primitive atmosphere on the Earth, were simple heterotrophic cells. These unicellular organisms survived on organic compounds present at the ocean floor. As organic matter begun to deplete due to a highly reduced environment (and organic material was not synthesized), cells gradually evolved from being heterotroph to autotroph. This change enabled the cells to use either chemical compounds or sunlight to synthesize organic material for food (Stanley 1973, Lazcano and Miller 1996). Plants, as sessile autotrophic organisms, are capable of harvesting light energy and converting it into chemical energy, which is used later as the carbon source. The process of synthesis of carbohydrates by green plants or pigmented organisms by utilizing carbon dioxide and water with the release of oxygen, in the presence of sunlight, is called ‘photosynthesis’. This process of light harvesting directly or indirectly supports all living organisms on the Earth. Significance and relevance of photosynthesis to the scientific community is obvious as ten Nobel Prizes pertaining to this research area have been awarded so far (Fig. 1). Thus, owing to the fundamental nature of this process, it is imperative to understand the basics of this ‘physico-bio-chemical’ event to ensure food security. It is estimated that human population on the Earth is going to cross 9.1 billion by the year 2050 and by the same time, the land available for agriculture in developed countries is going to be reduced by 50 million hectares This situation warrants a thorough understanding of the process of photosynthesis to ensure enough food production by crop plants. The present review is targeted to highlight the basic discoveries of the process as well as the recent reports pertaining to the study of photosynthesis, as influenced by salinity.