Debtors are people who have taken your stuff but have not paid for it yet. Debtors are people who "owe" you. So debtors are assets. When somebody buys something from you on credit they become your Debtor.

In this example we will sell some things to Bob on credit:

Journal - Page 1
Date  Description Post
Ref.
Dr Cr
2005
Feb
1 Debtors - Bob (Asset) 10
Sales (Income) 10

Later WHEN Bob pays us.

Journal - Page 1
Date  Description Post
Ref.
Dr Cr
2006
Feb
1 Cash (Asset) 10
Debtors - Bob (Asset) 10

Note that when a bank sends you a bank statement, they show you the position from the bank's point of view, not yours. So when you have a debit position, you owe the bank money - the balance is an asset of the bank. When you are in credit, the bank owes you money