This section of the Windows to the Universe web site provides information and images about the solar interior including detailed information about the different zones within the Sun, how energy is produced in the Sun through fusion reactions, and how energy is transferred from the core to the radiation zone and convective zone. Windows to the Universe is a user-friendly learning system pertaining to the Earth and Space sciences. The objective of this project is to develop an innovative and engaging web site that spans the Earth and Space sciences and includes a rich array of documents, including images, movies, animations, and data sets that explore the Earth and Space sciences and the historical and cultural ties between science, exploration and the human experience. Links at the top of each page allow users to navigate between beginner, intermediate and advanced levels.