[astura]

Secured cards work exactly like non-secured cards, the only difference is the bank holds onto collateral, usually equal to your credit line. You still have a bill to pay, minimum payment, due date, you can pay the minimum and carry a balance, rack up late fees, etc.

The collateral is only returned to you when you close your account or upgrade it to a non-secured card. You don't use the collateral for the monthly bills, just like if you rent an apartment you don't use the security deposit to pay the monthly rent.

[asavadatti]

Does the bank pay interest on the collateral? I'm assuming not

[yrxuthst]

Depends on the issuer. In this case they do not - see https://www.synchronybankterms.com/gecrbterms/pdf/Amazon.com..., section V