The terms "hardwood" and "softwood" refer to the type of tree the wood comes from, not the wood's actual hardness:
Hardwood
Comes from deciduous or evergreen broad-leaved trees, such as angiosperms, that grow more slowly than softwoods. Because of this, hardwood is usually denser and stronger than softwood, making it sturdier and more weather resistant. However, there are exceptions, such as balsa, which is a hardwood but also one of the lightest and least dense types of wood.
Softwood
Comes from coniferous or needle-leaved trees, such as gymnosperms, that grow faster than hardwoods. Softwoods include Scots pine, Western red cedar, and paraná pine.
Hardwood trees are more energy-dense, which means they will burn hotter, cleaner, and longer than their softwood counterparts
Oak is hardwood
Softwoods are usually less dense compared to hardwoods and generally absorb more moisture. Excess moisture promotes mould, fungi and algae, which if not treated, will be damaging to the timber's structure.
Ash is a hardwood
Question :
Does softwood burn hotter than hardwood?
Which type of wood is oak?
Is softwood waterproof?
Is ash a softwood?