In what way are the light-dependent and light-independent reactions of photosynthesis similar?

Photosynthesis is defined as the process by which plants makes their own food in the presence of sunlight and produces energy by utilizing carbon dioxide and water.  

Photosynthesis takes place in two main stages named the light-dependent reactions and  the light-independent reactions. Both light-dependent and light-independent reactions of photosynthesis are different from each other but they are having a similarity that is they both require chemical energy for the completion of process.

Light-dependent reactions occurs in the thylakoid membrane (present in chloroplast) in which the light energy is utilized to produce ATP (chemical energy)  and NADPH.  In the light-independent reactions which takes place in the stroma utilizes the products (ATP) of the light-dependent reactions to function. ATP provide the energy to form carbohydrates from CO2. After the energy is transferred, the remaining energy molecules  return to the light-dependent reactions in order to obtain energized electrons.

the national environmental policy act (nepa) is a united states environmental law that promotes the enhancement of the environment and established the president's council on environmental quality (ceq). the law was enacted on january 1, 1970. to date, more than 100 nations around the world have enacted national environmental policies modeled after nepa.