Book excerpt: This book provides a general overview and current state of the art of different types of metal oxide nanomaterials, either in nanoparticles or thin film structure. It covers from the development and optimization of different nanofabrication/synthesis techniques for nanostructures which are currently the attention of the research community, the study of the structure and interactions by different characterization techniques of heterostructured materials and the final impact in different applications such as nanotherapy, data storage, super magnets, high-frequency devices. The book’s 13 chapters provide deep insight into the intriguing science of oxide materials and include contributions on novel technologies to fabricate nanomaterials with a broad range of functional properties (semiconducting, magnetic, ferroelectric, thermoelectric, optical, flexible and mechanical). This book is intended to the experts for consolidation of their knowledge but also for students who aim to learn and get basics of nanostructured metal oxides in diverse forms.