When you bring an invoice from a supplier on to the system, the 'Money You Owe' account will increase. Accountants generally call this account 'Trade Creditors' or 'Accounts Payable'... we call it what it is.
When you bring in an invoice from a supplier that you haven't paid yet, the expense (and VAT if you are registered) will be recorded at that point in time and the Money You Owe will go up. When you subsequently pay the invoice from your business bank account, your bank transaction will reduce the amount you owe.
What's not included
Loans from banks should be categorised in to Business Loans.
Any Loan to a Director should be separated from this category.