As for any accounting software, everythings depend on accounts. In this case, each of these accounts will share transactions
The 6 more important account types are :
Assets : Money, cash, wallet, bank account
Liabilities : The opposite, debts, credit cards, etc.
Income : Any money paid in a asset or liability account
Expense: Any money withdrawn from a asset or liability account
: It is used to show the money your customers owe you and it gets back to zero once every customer invoices
: It is used to show the money you owe to your vendors and it gets back to zero once every vendor invoices