Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material, a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined 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 support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between 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, or wood chips or fiber.

Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper, and as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.

In 2005, the growing stock of forests worldwide was about 434 billion cubic meters, 47% of which was commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991 approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.


For a long time and even today, many buildings, mostly houses, have been made of wood. To build a house with wood, lumber is put together into frames that are the shape of each wall, floor, and roof of the house. Then the frames are placed into the shape of a house. Then the frames can be covered to make solid walls. Sometimes the walls are made of more wood.

When the outside of a house or building is covered in wood, the wooden pieces are usually flat and stacked. These pieces are called shingles. Wood is also sometimes used in other parts of the house, like doors and staircases. Wood is also used to make fences.


Carpenters make houses of mostly soft wood such as pine. For many kinds of furniture they use harder wood such as maple or oak. When someone builds something with wood, they usually paint it. Paint protects and beautifies the wood. Some people like the look of wood, so they put clear paint called varnish on it.

Some people make art with wood. Sometimes sculptures are built with wood.

Regular pencils are made of wood, with dark graphite inside for writing.


Wood is turned into paper in large factories called paper mills. The wood is first chopped into small chips and cooked with chemicals in large vessels. The chemicals separate a substance called cellulose off the wood fibres. The cellulose is then added with other chemicals and additives, and pressed into paper in large machines called paper machines. Most paper is made from pine, spruce and eucalyptus.