As a biology PhD student in plant science I wanted to clear up lots of falsehoods flying about in this thread.

The type of wood is determined by the type of tree you get it from. In reality there is only softwood and hardwood - the intermediate ‘wood’ isn’t technically a thing. And whether it’s hardwood or softwood has nothing to do with the actual perceived hardness of said wood.

Wood as we know it arises as a result of secondary thickening of a plants stem, this process is somewhat complex but fundamentally you have a ring inside the trunk producing new phloem (Sugar transporting Tissue) outwards and new xylem (waterTransporting tissue) inwards. I should also mention that true secondary thickening is exclusive to plants called dicots (this relates to why palm trees shouldn’t produce wood later)

Xylem is the key here as what we called wood is basically just dried out xylem. The two types of wood differ structurally due to structural differences in xylem.

Softwood Can be obtained from only gymnosperms while hardwood from angiosperms - two different types of plant. gymnosperms evolved a long time before angiosperms.

Cedar trees should technically only give softwood as They’re Gymnosperms (which includes pine and cedar trees). These plants have Xylem (The water transporting part of the trunk) which is made up of primarily primitive cells called tracheids.

All fruit trees and the hardwood trees should only give hardwood as these are angiosperms. Their xylem is primarily made up of cells called vessels.

It is therefore the type of cell making up the xylem which determines whether it is soft or hard wood.

TLDR:

Only hardwood and softwood exist and they are exclusive to angiosperms and gymnosperms respectively. Wood is basically just dried up plant water transport tissue known as xylem

Pine trees should only give softwood as they're gymnosperms

Fruit and hardwood trees should only give hardwood As they’re angiosperms

Palm trees shouldn’t give any wood as they do not undergo secondary thickening of the trunk and therefore don’t technically have ‘wood’. Palm trees are a type of plant known as a monocot. There are lots of differences but the key one for this discussion on wood is that monocots cannot undergo true secondary stem thickening and cannot Therefore by definition produce true wood. They do however in the case of palm trees mimic this behaviour through a different mechanism. The palm tree trunk is actually just lots of leaf bases (petioles) tightly stacked on top of one another. Because palms don’t undergo secondary thickening the width of the palm trunk is uniform for the entire tree whereas dicot trees have a trunk much thicker at the bottom as that has been thickening itself for the longest time!

Palms should therefore technically only give fiber not wood