[TheCoelacanth]

Credit cards are unsecured debt. Hence they have very high interest rates because there is a fairly high risk that the debt won't be repaid.

Mortgages are secured debt. If the debtor fails to pay back the debt, the house can be seized and sold to cover the debt. That makes it pretty low risk, but there is still some risk because house prices sometimes drop precipitously, so it might not always cover the whole loan.

Apple's debts are secured by cash sitting in a bank account. There is literally next to no risk of default. They will get an even better interest rate than someone very creditworthy will get on a mortgage.