The variability of life on earth is known as biodiversity. It is primarily concerned with the measurement of the variation at the genetic, species and ecosystem level. Important sub-fields of biodiversity include terrestrial biodiversity and marine biodiversity. Terrestrial biodiversity is found in the areas near the equator due to warm climate and high primary productivity. The diversity of all living beings is based on their habitat and factors such as temperature, altitude soils, geography, soils, and precipitation. The field known as biogeography is also related to the biodiversity. It is the study of the spatial distribution of organisms, species and ecosystems. This book is a compilation of chapters that discuss the most vital concepts in the field of biodiversity. Such selected concepts that redefine this field have been presented in this book. The topics covered in it offer the readers new insights in this field.