When one wood is lighter in colour with lower density, the other wood is darker with higher density. They are.
In dicotyledonous stems, during intra stellar secondary growth, a ring of cambium called vascular cambium is formed. In the plants growing temperate regions, the activity of vascular cambium is influenced by the existence of maximum seasonal variations. In the spring or early summer, due to the existence of favourable conditions, a large amount of secondary xylem is formed. it is called Springwood or early wood. It is lighter in colour with low density. In the autumn season, due to the presence of unfavourable conditions, less amount of wood is formed. it is called autumn wood or latewood. It is darker in colour with higher density.