This book has been especially designed for higher education and covers complete syllabus of UPSC Civil Services (Main) and States Public Service Commission examinations. This book may also serve as a comprehensive source of knowledge for graduate and postgraduate students of geography, at the same time it is useful for teachers and researchers of physical geography. In this book author tries to show how physical geography impacts humans, and how humans impact physical geography. The text emphasizes five essential themes to demonstrate the major roles for the discipline-Geography as a Geophysical Science, Geography as the Climatic Science, Geography as the Ocean Science, Geography as the Biogeographical Science and Geography as Environmental Science. The book is written in an easily accessible style with generous expositions of key claims and arguments, and with thorough cross-referencing between chapters, thus conveying to students the logic and integration we recognize in the broad field of physical geography.