The general theory of relativity, as developed by Einstein in 1915, was not only a mathematical marvel, but also a sound physical principle that changed completely the way one looked at classical physics. The fact that it resolved an outstanding problem of Newtonian astrophysics, and further predicted new effects tht were testable, was excellent for any physical theory. Developments in astrophysics and cosmology, post-general relativity, in the last one hundred years are very impressive. While the solar-system based experiments and observations have increased accuracies of tests, the applications beyond the galaxy and into distant space at cosmological distances have established the theory to be a unique theory of space and time and the best available for understanding the universe. While the astrophysical applications will be taken up in a later chapter, the solar system and near earth phenomena will be considered now, after first obtaining some basic exact solutions of the field equations.