A Design Load is any load scenario that is applied to a Zone or Joint to be Sized/Analyzed against. There are two categories of Design Loads:
FEA-Based Design Load Cases: Defined directly from FEM subcases; used to tell HyperX how to work with element-forces resulting from FEA. This is the most common type of load scenario.
Non-FEA Design Load Cases: Defined manually by the user within HyperX; not originally derived from a FEA subcase or combination of FEA subcases.