What exactly is a secured creditor?

Answer: Here is a basic definition: A secured creditor is a company [or an individual] that has a claim against a debtor company that is secured by the pledge of collateral and/or a lien on one or more assets of the debtor company.

In contrast, an unsecured claim is one in which a creditor has no special assurance of payment. Typically unsecured creditors make sales on open account terms based on the creditor's assessment of the creditworthiness of the debtor company under consideration.