Major features of QuickBooks Online (QBO) are explained in one single Chart below:
Click on the screenshot below to enlarge it
Dark Blue navigation bar on the left for customer center, vendor center, all transactions including printing checks, run standard reports, setup and print sales tax, and buy apps.
Company Gear – top half of blue screen for settings (preferences), chart of accounts, products and services (item lists), bank reconcile, import and export data, and manage user access.
Middle plus (+1) sign – bottom half of blue screen to enter all transactions from invoicing to billing to journal entry, also bank deposits and bank transfers.