Italian national insignia

[leefif1953]

What is the difference (besides one has corners) between the Fascist symbol in the circle and square?

 

[Parmigiano]

The round white insignia was the one used by Italy during the fascist era until september 1943.
After the armistice, the aviation who sided with Mussolini and the Germans (RSI - Repubblica di Salò) adopted the white square markings, while the co-belligerant af went back to the red-white-green roundels.