Fascism is a form of far-right, authoritarian ultranationalism characterized by dictatorial power, forcible suppression of opposition and strong regimentation of society and of the economy which came to prominence in early 20th-century Europe.
Other than the definitions always include the term "far right" the description sounds just like our left.
Research the two italians who made the philosophy of fascism.
Here a tid bid both of them were socialist who discover international socialism could never work since people identify with their nation more then their class. Which became clear from the outbreak of WW 1
Purely from an academic point of view there is a big difference between national socialism and every other form of socialism. It doesnt involve centrally planned economy and their currency is backed by labour.
Another difference is motivational. These two were really hoping to fix their countries whereas pretty much every other form of socialism is motivated by wanting to subjugate and control people.
All forms of socialism wants to subjugate the private domain as they feel the public/collective/state/union/corperation/syndicate and so on should control the means of production.
Socialism has a major schism between international and national but from their they have forther breakaways of how to accomplish it and on behalf of who.
Just like Christianity has 100 of different version but they all have a core belief.
It’s all a form of Hegelianism
Who hated individuality and espoused authoritarian collectivism