Fascism, at least in the word’s common usage of today, is understood to be a form of socialism in which a centralized authoritarian regime or dictator, one which places nation/race/religion above all else, controls a society through strict regimentation and the suppression of dissent and opposition.
The term “Islamofascism” is generally understood to describe an authoritarian political system based on Islamist beliefs.
In fact, once one takes a closer look at the Islamic State, it becomes clear that they are indeed socialists, of the Islamic variety.
Their goal is to establish a Caliphate, or one giant, all-inclusive Islamic nation, in which everyone lives under strict Islamic Sharia law. Non-believers and dissenters are driven out, extorted, forced to submit and convert, or killed. Opposition is not tolerated.