This book is built up from a course of lectures given at the Physics Depart-ment of Florida State University and has the aim of presenting the indis-pensible material in a direct and concise form. It does not require previous knowledge beyond the basic ideas of special relativity and the handling of differentiations of field functions. It will enable the student to pass through the main obstacles of understanding general relativity with the minimum expenditure of time and trouble and to become qualified to continue more deeply into any specialized aspects of the subject that interest him.