A major starting point
Cascading is a major starting point in the bio-based economy. Cascading means that you extract the most valuable components from biomass first. The most valuable biomass components can be utilized for complex chemical processes, such as production of medicines or chemicals.
Biomass that is unsuitable for these high technology processes, often still can be used as energy, like for example as resource for electricity or heat production. To use valuable biomass components for this application would be a waste, because then all components would not be used optimally.