The term hardwood is used to describe wood from broad-leaved angiosperm trees, mostly deciduous, but not necessarily, in the case of tropical trees. Hardwood contrasts with softwood, which comes from conifer trees. On average, hardwood is of higher density and hardness than softwood, but there is considerable variation in actual wood hardness in both groups, with a large amount of overlap; some hardwoods (e.g. balsa) are softer than most softwoods, while yew is an example of a hard softwood. Hardwoods have broad leaves and enclosed nuts or seeds such as acorns. They often grow in subtropical regions like Africa and south-east Asia, but also in temperate regions such as Europe and North America. The dominant feature separating hardwoods from softwoods is the presence of pores, or vessels. Examples of European hardwoods from evergreen trees include holly (Ilex aquifolium), boxwood from Buxus sempervirens and oak from the holm oak Quercus ilex. Common deciduous European and North American hardwood species include the oaks (Quercus species), beech (Fagus species), ash (Fraxinus species), maple (Acer species) and cherry (Prunus species). Important tropical hardwoods include teak (Tectona), mahogany (Swietenia), iroko (Chlorophora excelsa), ebony (Diospyros ebenum) and rubberwood (Hevea brasiliensis).
Hardwood species are more varied than softwood. There are about a hundred times as many hardwood species as softwoods. The vessels may show considerable variation in size, shape of perforation plates (simple, scalariform, reticulate, foraminate), and structure of cell wall (e.g. spiral thickenings).
Solid hardwood joinery is expensive compared to softwood. In the past, tropical hardwoods were easily available but the supply of some species such as Burma teak and mahogany is now becoming restricted due to sustainability issues). Cheaper "hardwood" doors, for instance, now consist of a thin veneer bonded to a core of softwood, plywood or medium-density fibreboard (MDF).