Mechanic

Do you mean the difference between FCFF and FCFE?

Regarding, starting with CFO or NI is the same thing. NI plus non-cash charges (e.g. depreciation, amortization) gets you CFO anyways.

So, the 2 below are same
1. FCFF = CFO + ....
2. FCFF = NI + Non-Cash charges + ....