When an invoice is created in Quickbooks, how is it automatically categorised?

For an invoice transaction type in Transaction Report, in the account column, there is "Uncategorised Income", and in the Split column, "Debtors". Does Quickbooks credit the first and debit Debtors? Does it mean that when I review the bank transaction, I need to categorised it as Debtors? And how to change from Uncategorised Income to Sales?