Many of the people who use terms such as 'communism', 'socialism', 'free market', etc. have never heard of the original thinkers behind these ideas, and even then almost none have read the original texts (including me).
So I am going to attempt to define these terms as they relate to modern life; however, with an eye to how they were first created, because that is still relevant:
Socialism: The mainstream left, (not far left) and general celebrity culture populism are nearly inseparable in my opinion. Perhaps it fits with some of the collectivist views the modern left have (but Marx did not apparently!)
But how it begun, as I have described, as a temporary stop between capitalism and communism. So what it basically is is a government that gives money and resources to the people and intends (we cannot say actually does) intends to make things 'more equal'.
It's a general idea, and it does generally, as most of the populist left do in my opinion, completely neglect the fact that markets exist. Marx did not talk about making money he was hung up on justice, value.
Communism: A utopian idea put forward in Karl Marx's theories that depends on the good will of the general man, without the existence of government, where all beings are equal and individual... This can not be said to have ever have existed, since all supposedly communist societies have a lot of government power involved. There is no evidence that it is possible for it to exist at this stage in our history.
Liberalism: A basic commitment to free speech, a capitalist economy and democracy, which defines the society where these principles are available away from one that doesn't have them (which are often somewhat 'undeveloped')
Neo Liberalism: When sophisticated Liberal societies use abstract concepts to cover the fact they are actually taking more freedom away than they are giving. (Also known as politically correct)
Fascism: When the government controls both the government and ideology of the country in an almost religious sense through propagandising the media. Often incorrectly defined as synonymous with racism, but a non racist fascist government is possible. Perhaps this definition can be extended to those cults with a political aim that brainwash their followers and propagandise not allowing any other influences. However, my understanding is that fascism is a political term, so would have to apply to an active government
Racism: The belief that one race is different enough from another to be superior and that one's own superior race should enslave another inferior race.
Tyranny: When the government controls the populace through force and the threat of force.
Libertarianism: The deep belief that people should be free, associated with what has euphamistically been called Conspiracy theory, Climate realists (i.e. skeptics) and often the right wing. Opposed to collectivism. People that believe if a fact is true it should be recognised, and are not swayed by non factual emotional arguments about sensitive subjects.
Free Market: Although has been associated with de regulation, a more accurate definition of Adam Smiths use of the concept is de- regulation except for the regulation needed to prevent crime and injustice. However, it really means using market principles and common sense in your managing of a society.
Note: Feminism was originally 'liberal'. But is now defined under either Neo Liberal or Libertarian, depending on the individual.
I.e. Feminism is based on the idea that women are oppressed in some way and action is needed to solve this. Libertarian feminists look for 'reality' and focus on the real facts of where women are truly treated badly, like in the Cologne migrant scandals. Neo Liberal feminists use 'feminism' as an excuse to restrict the right of free speech by activism against anyone who says the wrong thing.
Obviously I know a little less about feminism than the others but felt I ought to include it.