Wood

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Wood is a natural, lignocellulosic material derived primarily from the secondary xylem of trees and other woody plants, where it provides mechanical support and in the functional sapwood, conducts water and dissolved minerals. Being a natural material, it is characterized as an organic material – a natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin and hemicelluloses that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree, it performs a mechanical-support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients among the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fibers. Wood has been used by humans since prehistoric times for fuel, tools, weapons, and shelter, and later as a construction material and for making furniture, paper, and other products. Its use predates recorded history, with early humans exploiting branches, poles, and logs for simple tools, hunting weapons, shelters, and firewood. More recently, wood has also emerged as a feedstock for the production of purified cellulose and its derivatives, including, among many others, cellophane and cellulose acetate. In English language, several terms are synonyms with wood, including timber, lumber, planking, boards, planks, logs, firewood, kindling, fuelwood. The terms xylon, xylem, derived from the Ancient Greek word ξύλον, refers to wood but is uncommon in modern English. These terms denote specific forms, uses, or products of wood. As of 2025, the growing stock of forests worldwide was about 630 billion cubic metres.