The Banking page is where you connect your accounts and download transactions. This is as known as "Bank Feeds". Why connect your accounts? Because it saves you time, reduces manual entry errors, and ensures your QuickBooks .
Your bank and credit card companies store transaction information about the money going in and out of your accounts. You want that same information in QuickBooks online because it's part of your business finances.
Instead of manually entering the data, let QuickBooks online get the information for you. You choose whether to add transactions as new items or match them up with items you already entered in QuickBooks online. After you are connected and the account is configured, QuickBooks online downloads your bank data automatically, usually at least once daily.