Storylines are statements that describe the context and rationale for the Performance Expectations (PEs) in each grade band and section.
"Bundles" are groups of standards arranged together to create the endpoints for units of instruction. Bundling is just one step in a curriculum development process; many other steps are required to create instructional materials designed for the NGSS.
These documents provide example storylines for the DCI arrangements of the standards.
These documents provide example storylines for topics arrangements of the NGSS.