Algae grow in a wide range of habitats starting from freshwater lakes to rivers and oceans to deserts. They serve a very important role not only in the aquatic ecosystem as primary producers but are also responsible for release of oxygen into the atmosphere. Algae and their products are widely used in food, agriculture and a number of industries. In recent years it has been realized that algae can play a major role in environment and biotechnology. The present book contains 34 chapters covering diverse aspects of algae. Hence, this book will be very useful for the students, researchers, university teachers and people from a wide spectrum.