Acronyms here and there, meaning different things. CFM stands for Cubic Feet per Minute, of gas and that means not exclusively air. This is not true at hundred per cent because higher densities and other conditions would affect the measurement. However, when you do not have a reference of the fan power, wattage or CFM is a good indication to compare and choose with the right specifications for the task.
It's very common to see computer fans having a CFM specification, with values about 10-30 for 8 centimeters, and 20-50 for 12 cm. Someones try extreme air flow up to more than 120 CFM with 14 centimeters.
Cheap fans for home, those plugged directly to 230V or 110V exhibit a great air flow even compared with industrial appliances. Normally 1500 to 5000 CFM or even much higher in some models.
Other fantastic feature of the usual fan is how the electric motor last for ages.