ABSTRACT
Much of our current understanding of the early universe comes from the application of Einstein's general theory of relativity. The general theory of relativity is widely acknowledged as one of the most beautiful creations of the human mind. It is also one of the most fiendishly difficult physical theories to master. An adequate treatment, even at the level aimed for here, would require a book of its own 1 . The best that we can manage at the moment is a brief overview concentrating on the main ideas that are needed for cosmology.
