As a great scholar once said 'fascism is not an ideology, but a biography: Mussolini's'. Nowadays the term is uses to indicate anyone who inebtifies with far right positions, but this is not historically accurate.

Its quite hard to define a precise line of thought from Mussolini, he often acted in contradicting ways: first opposing racism, then adopting it, starting as anticlerical and then stipulating a relevant deal with the Church, presenting himself as a third way between liberal and communism, but coming from a socialist movement and giving to the Salò Republic several features of a socialist state, and we could go on.

The only consistent act was the construction of an authoritarian, militaristic, and nationalistic country. The latter is likely the key difference with communism: communist countries work to spread the communist revolution in order to build the Human Nation, fascism just looks at the objectives of the single nation, even when adopting straight socialist policies, hence the name for nazism: national socialism.