Usually large, deciduous trees, occasionally also shrubby. Many of the approximately 200 species are summergreen and others are evergreen. Oak are very widespread. If the oak grows enclosed in forest stand, it forms a 12 to 15 m tall trunk free of branches, with a diameter of 40 to over 100 cm. The Spessart oak is especially well known. By the time these trees are felled from an age of around 240 years, they have reached heights of up to 40 metres.

Aside from its even, mostly pale yellow colouring, the width of the growth ring is a decisive attribute of oak. Wide growth rings of over 3 mm signify coarse and hard wood. Narrow growth rings of 1 to 2 mm result in soft wood, while ring widths between 2 and 3 mm produce medium-hard material. The heartwood is weatherproof and very durable. German oaks have a 2.5 to 5 cm-wide, yellowish white sapwood, which clearly contrasts with the greyish yellow heartwood. Depending on the origin and species, the heartwood later darkens to become a light to dark brown colour. Freshly sawn timber can often have a light reddish tinge.

Face veneer. Named after its intended use, for example, for the outer surfaces of furniture.