Cashflow is all the money coming in to you. Net income is cashflow minus all expenses.

cash flow = gross incomes
net income = gross incomes less costs

Cashflow is cash the company has paid or received. Net income is a result of income and expenses recorded by the company, which may or may not involve cash.

For example, an accounting company completes a client's tax return and bills him $300. Excluding any other transactions, on that day they have $300 of income but no cashflow. 30 days later, the customer pays his bill. On that day, the company has positive cashflow of $300 but no income.

Larry (CPA)

Net income is the net profit after all material costs and operating expenses are paid. This has to be further defined, "After Taxes".

Cash flow is the amount of cash that is generated from sales.
This is reflected in gross sales , along with materials and expenses paid out. When profits are maintaind, there should always be a positive amount of cash on hand.

Accounts receivable has a great effect on cash flow. When slow collections exist, cash flow can become negative, placing the business in the need of loans or additional capital.

Excessive draws by the owner or management has the same negative effect.