Happy to give you some details about the difference between the banking and the app transactions.
The Banking Transactions refer to the ones downloaded from your connected bank account (the Online Banking feature in QuickBooks). They don't really affect your books until they are matched or categorized.
On the other hand, the app transactions are the ones recorded in QuickBooks. They are usually created through the functions from the + New button.
App transactions could also mean that they are imported from a third-party program. They usually affect your books as soon as they are imported to QuickBooks Online.
Though, some apps' import processes behave like the Online Banking feature (as mentioned before, they don't affect your books until they've been matched or categorized).
After dealing with your transactions, ready to reconcile your bank account? Check this guide to walk you through the process: Reconcile an account in QuickBooks Online.
Looking for new things to learn in QuickBooks Online? Let me know the details below and I'll help you out.