The Load Set Definition is used for previously grouping common load definitions for more complex analysis. This can be more advantageous than entering the load data directly in Load Case Definition because the Load Sets can be later assigned to the load cases altogether with various lines with load definition data. The Load sets may also be separately factorized when assigned to a load case. The grouping and factorization might allow users to create faster load definitions. As shown in the screenshot below, this can facilitate the work for load definitions in analyses that use construction stages.