This book provides a detailed overview of high entropy materials and alloys, discussing their structure, the processing of bulk and nanostructured alloys as well as their mechanical and functional properties and applications. It covers the exponential growth in research which has occurred over the last decade, discussing novel processing techniques, estimation of mechanical, functional and physical properties, and utility of these novel materials for various applications. Given the expanding scope of HEAs in ceramics, polymers, thin films and coating, this book will be of interest to material scientists and engineers alike.