COMEX is a precious metals brokerage house (I believe that would be the correct terminology), APMEX is a precious metals DEALER.
Be kinda like the difference between buying WalMart shares from Fidelity (brokerage) or buying flip flops at Wal Mart (dealer).
Kinda,,,,maybe.
No, I think it’s closer to wholesale vs. retail. You can (theoretically) buy a silver futures contract on COMEX and have it delivered. If they have any to deliver. But the minimum order is 1000 oz, a “mini contract,” or 5,000 oz, a regular contract. APMEX will sell you 1 oz.