The cashflow can support the investment itself, which is so called breakeven or positive cashflow. The positive part can be used to the next levels;

The positive cashflow is enough to support the living expense, which means you can afford to quit your daily job if you hate it or if you want to focus on things you like. If there is still surplus, it enters the next level.

The positive cashflow can be contributed to the new investment, which means you can grow bigger (if you want it).