Assets = Liabilities + Owner's Equity. This is the accounting equation.
Assets example would be checking account balance, inventory, land and equipment, and accounts receiables (unpaid invoices)
Liabilities would be loans, unpaid bills (accounts payable), sales tax payable, payroll tax payable, and credit card balances
Equity would be retained earnings, owner's draw and owner's contribution.
In QBO, retained earnings will automatically post your income as it crosses over a new year.