There are so many terms that, from a libertarian standpoint are basically just "big government". But are quite different philosophies from one another.
Socialism is to allow people some general freedoms over much of their personal preferences. But for the government to play Robin Hood whenever this is a "fairness" issue. Grants, food stamps, public schools, public gyms, are all socialist in nature. Ancient Athens was very socialist. Pure democracy, over time tends to become socialist, even to its own destruction.
Facism is centralized planning of business. "Too big to fail" is the entry drug for full out fascism. fascism says ... big business is good, but it has flaws (the 1% complaint you hear out of OWS). Flaws which can be fixed by letting the government take over in any way they see fit. Facism says that competition in businesses is not necessary, because the problems fixed by competition can also be fixed by direct intervention of the state.
Communism is centralized planning of all resources, and having the state make the "important" choices about what is good for people. It assumes people are just sheep who need to be shepherded, and then everything will be sunshine and lolly-pops. Communism requires no religion, because the state cannot be accountable to God.
In every case, it is liberty that must be compromised in some form for any of these systems to advance.