Wood
The Wood is the part of the trees covered by the bark, in the case of the wood concerning to the xylotheque, it is a piece where we can observe the color and the shape.

Hardwood
To define what a hardwood is it is necessary to enter in terms of botany. Broadly speaking, hardwoods are broad-leaved species.
The hardwoods, also known as angiosperms, whose name comes from the Greek and is scientifically known as Angiospermae, are plants with flowers (although they do not always correspond to the common idea we all have of a flower), which produce seeds enclosed and protected by the wall of the ovary (carpels) that later becomes fruit. They form the largest group of their kind in nature and are made up of herbaceous, shrubby or arboreal plants, e. g. oak and chestnut.

Conifer
Conifers are trees or shrubs: they are part of the gymnosperms,evergreens whit aciculate leaves, their fruits and branches have a cone shape. e.g. cypress and pine.