This book tries to debate on the significance of circular economy, underlying the necessity to change our way of producing, consuming, and traveling on a daily basis. The passage from a linear economy to a circular economy will help us to reduce the degradation of the environment for avoiding future disastrous consequences, such as depletion of biodiversity, scarcity of raw materials and drinking water, rising waters, etc. The circular economy, therefore, involves designing a product so that it can be recycled or its components reused. Reuse consists of introducing the product back into the economic circuit in its original condition; repair makes it possible to fix a broken good; and recovery consists of reusing its components. This is the significance of the so-called 3R strategy, illustrated in this book.