What the MAIN difference between systems prototyping and throwaway prototyping?

Systems prototyping involves users while throwaway prototyping does not

Throwaway prototyping involves users while systems prototyping does not

Systems prototyping is a rapid application development methodology; while throwaway prototyping is not

Systems prototyping works with users to quickly develop a simplified working version of the proposed system; while throwaway prototyping focuses more on exploring design alternatives

Throwaway prototyping develops systems that will be use as $$stop$-$gap$$ systems $$ and generally for less than six months; while systems prototyping results in systems that will be used extensively for several years.