Thank you for the opportunity to help you with your question!
A debtor is someone (or a party) who owes money to another person (or another party). In this case you can think of a party as being for example a bank or any other financial institution like credit unions.
If i for example i borrow money from my friend , I'm a debtor to my friend.
A creditor on the other hand, is a person or a bank that has lent money to another person. If for example i borrow money from a bank, the bank is a creditor.
or if i borrow money from my friend, my friend is a creditor and I'm a debtor.
Please let me know if you need any clarification. I'm always happy to answer your questions.