Hardwoods or hard timbers are generally denser and therefore durable than softwoods or soft timbers. You are able to identify hard timber trees by characteristics such as their leaves because these types of trees have broader leaves than soft timber trees.
Hard woods are often darker in colour than softwoods and most are denser due to thicker cell walls although this does not mean that all are denser than soft timbers.
A lot of people like buying hard wood furniture, wood panelling or floors because the majority are fairly dense which means if looked after well they last a long time and are more resistant to dents and scratches.
These woods are also good for making really strong woodwork joints such as the mortise and tenon joint because they are often dense.
Softwoods are not necessarily soft or less dense, just more likely that they are softer than hardwoods. The differences in appearance of soft timbers compared with hard woods include things such as usually being lighter in colour and usually softer
Soft woods come from trees that are conifers meaning that their leaves are usually needle shaped instead of broad like are on hard timber trees leaves.
Soft woods absorb things better than most hardwoods such as adhesives or finishes and it also makes it easier to treat soft woods therefore increasing their durability. This makes them good for furniture making as long as they are regularly maintained.
Pine is a good example of an affordable soft timber that is also denser than some hard timbers which is why it can be a very useful product for interior furniture.