Wood
Wood comes from the body of a tree or bush. It is the solid parts found on the inside of trunks, stems, and branches. There are two major ways to harvest wood. To cut down the entire tree and use the trunk as the main wood source. Or to coppice a tree and use the branches as the main wood source. Cutting down a tree will generally kill it. Coppicing will keep the tree alive for many decades if done right.
Types of wood
Wood can be roughly split into two major categories, each with their own specifications.
hard wood
Hard wood comes from deciduous trees.
Soft wood
Soft wood comes from coniferous trees.
Uses
Construction
The building of houses, floor and roof beams are still generally made of wood. In the past roofs where kept up by wooden beams too, and walls where covered, partly, in wooden planks.
Mining
Pinewood, was for decennia used to support mineshafts, as this wood is exceptionally good at compression. And it starts to crack audibly before it breaks. Giving miners a slim change to escape an impending collapse.
Fuel
Fuel to heat homes, and for cooking. They used offcuts or coppiced branches for this. Wood can also be used to power vehicles, via a steam boiler, but normally more high-density energy is used for that such as coal and oil.
Fake biomass fuel
The original idea of burning cutoffs of wood harvest in an electricity plant is not a bad idea in principle. But there are no rules on what IS cutoffs. So because of the ever-growing hunger of the world for electricity. And the demand to make it green has resulted in a tremendous demand for biomass fuel. And as a result whole forests get cut to be shipped around the world, to be burned for electricity. Under the label that it is waste that is being recycled. Which is a farce.
Paper
Eventhough paper is 80 to 90% recycled out of old paper it still needs new material, wood pulp is used for this. Offcuts, branches and such are chopped up to flakes and pressed into bales and shipped to paper factories.
Floors
Floors are still mostly made out of hardwood.
Furniture
Either all out of wood such as tables and chairs and cabinets, or with a wooden frame such as couches and armchairs.
Utensils
Spatulas, spoons, ladles, bowls, plates. Forks, cutting boards.
Ships building
If there is one object where it matters what kind and quality of wood is used, it is in ship building.
Art
Such as panelling with fancy grain patterns, carvings and sculptures.
Does the wood used for shipbuilding come from certain species of trees only?
Yes. But there are who bookshelves filled with information about that. I wouldn't even know where to start.