What is the difference between hardwood and softwood?

Softwood is coniferous (like pine) meaning that the tree grows quickly and has large growth rings. This makes for a softer structured material that is easy to cut.
Hardwood refers to to non-coniferous, often exotic timber that takes a long time to grow with very dense growth rings. This provides a strong material to work with. Mostly used for features in furniture like handles, profiling, feet and support details.