Wood is the primary reinforcing and nutrient-conducting tissue of trees and
other plants and is one of the most abundant and versatile natural materials. Wood produced by
many botanical species, including both gymnosperms and angiosperms, comes in a variety of colors
and grain patterns. It is strong for its weight and is electrically insulating and has desirable
acoustic properties. In addition, it provides a sense of "warmth" that competing materials such
as metal or stone lack, and is relatively easy to work with. As a material, wood has been used
since humans appeared on Earth. Today, despite technological advances and competition from
metals, plastics, cement, and other materials, wood retains its place in most of its traditional
roles, and its serviceability is expanding through new uses. In addition to popular products
such as lumber, furniture, and plywood, wood is a raw material for wood-based panels, pulp and
paper, and many chemical products. Finally, wood is still an important fuel in most parts of the
world.