Think of it as "confirmed " equity, much like the equity a house has. ( this can go up or down with the market value )
As an unfinished house has an inferred value ( equity ) no bank will lend against that , it has to complete, finished.
So, to, a JORC report " completes " and confirms a " value "of in-ground resource and so funding can be arranged by a preferred lender, based on something tangible, and not inferred.
Cheers