The sun is the primary source of energy that organisms need to live.  organisms such as phytoplankton, and plants are primary producers who transforms the sun energy into usable energy for consumers.  At each stage of the energy pyramid only 10% of the energy is transferred, and the other 90% are wasted in thermal energy.  for example if the sun gives phytoplankton 100m² of energy the Red Cod would only gather 10m² of energy.  If a dolphin was to eat the red cod the dolphin would only gather 1m² of energy.  In this food web the primary producers are marked in orange boxes.  The red, and brown boxes mark the primary consumers who are the animals that mostly feed on primary producers.  The purple boxes are secondary consumers who feed on primary consumers.  The Light blue boxes are the top predators in this food web, and they get the least amount of energy so they have to eat the most.  The arrows show the flow of energy from the source all the way to the top predators.