Income is what I have left over after my costs are paid. Income = Revenue - Expenses.
Cash-in is all money coming in (loans, credit cards, wages, sales).
I may get money from credit cards or loans, but debt is NOT income.
Revenue is all money received or coming in later (wages, sales, commission, accounts receivable (debts owed to me))
Income is based on Revenue. One easy way to remember income: the government will (likely) tax it.