Essential oils are simply the volatile oils of plants. These are concentrated liquids contain many terpenes, alkaloids and alcohols etc. Various compounds of essential oils have bioactive properties such as antimicrobial, anti-cancer, anti-diabetic, anti-viral and anti-fungal etc. This book describes the sources of essential oils, extraction and production method, characterizing tools, bioactivity, and various applications in the field of industries, daily usage, agriculture, health, and food. Presents the minimally explored biomolecules of nature. Contains content from worldwide experts in the field. Has up-to-date reference material, including websites of interest and information about the latest research. Can fulfil the demands of academicians and industrialists.