Wood is a fibrous material with fibers running the length of the wood.It's 55% cellulose and 28% lingin resin, which holds the structure together. Thins means that wood is classed as a 'natural fibre reinforced polymer

.4 stages of processing wood.
1. Harvisting - the cutting down of trees
2. Conversion - Cutting trunks and large branches into boards - Slab sawn or Quarter sawn
3. Seasoning - Releasing of the moisture content of the boards - Natural or kiln seasoning
4. Board preperation - sawing the boards to size and planing them e.g PAR (planed all round)

Slab sawn
Not much waste. Not very stable - likely to warp and twist. this is because the grain will want to form a straight line so it will bend in the opposite direction to the grain.
Quater sawn
More waste than slab sawn boards. More stable - less likely to warp and twist.Used for expensive hardwood timbers.Produce a more attractive grain.
Rough sawn timber
When timber is sawn it is measured in imperial units but once it gets planed it is measured in meteric units.
Edge Joints
Carpenters tend to edge joints of narrower timbers, alternating the direction of the grain, to produce wider, more stable boards.