Whenever you hear the word "Capitalism" replace it with "the private individual ownership of person and property", whenever you hear the word "Communism" replace it with "the public universal ownership of person and property".
In one case ("Capitalism"), you have exclusive ownership of your body and belongings, and other people have exclusive owner their bodies and belongings, "ownership" means "control", which means that any interaction with your person or property requires your permission, or it is illegal.
In the other ("Communism"), you have exclusive ownership of nothing, everything (and everyone) is instead owned communally by all people, everything is decided by the majority, and any interaction with anyone or anything must be based on what is most commonly agreed upon in order to be is legal.
Socialism is the stage in between, which most communist-aspirant countries never seem to get out of, und socialism, everything (and everyone) is owned by some central governing authority (they hate calling it "government), which represents the most common will of the people, but in actually just wields absolute authority with no interest in ever running out of excuses to give it up.
If Communism is direct democracy, then socialism is the representative variant of it, tyranny with the very transparently false image of "governance by the governed", much like our own government, to be frank.
Night-Watchman State Minarchism is the absolute extreme of capitalist government, you can't go further beyond this without going into anarchist territory, people who support it feel like the name should just be "Capitalism" since everything else falls short of their ideology, and NWS Minarchism is simply a label adopted for ease of communication, speaking of which...
Anarcho Capitalism is to capitalism what communism is to socialism, there is where ownership , instead of a representative body being charged to guarantee and enforce the principles of ownership and consent, these principles completely replace government, and instead everyone just agrees to only interact with the person or property of the others, or the interaction is illegal. AnCaps tend to think that this is a hard reset on civilization back to the first way people governed their interactions, like the Minarchists, these guys have a word they prefer, "Voluntaryism", but use the name they are known by here for communication-clarity purposes. They also tend to respond to the idea of feudal states eventually emerging from the implementation of their ideology as something they have little problem with.
Which leads to the concept of Neo-Monarchism, the idea that a return to monarchy is a good idea because when the government and it's people are someone's personal property, inherited from their ancestors and to be passed onto their descendants, then the leader would have more interest in maintaining it in good condition, many AnCaps who think about their ideology and where it might lead can just make the leap to this concept, and many did, even creating their own board for it, they also tend to cross-pollinate with the other ideologies mentioned here.
Egoism (or AWA - "anarchism without adjectives") is anarcho capitalism and communism without regard for consent (communal or individual), allowing all interactions based solely on their physical capability, and equates ownership solely to possession, basically, everything is a free for all, associations can be voluntary (as in the most nationalist/isolationist forms of capitalism) or coerced (as in the more globalist/expansionist forms of communism), it's just straight up "no rules but the rules of nature/reality". These guys disagree with the AnCaps and think they TRULY represent the primal order, as an irony, they tend to be simultaneously the most anti-government (even looking down on moral restrictions in addition to laws) and the most pro-government (since they tend to believe that their ideology is always in play, it is what TRULY governs everything already, and what we see is the end result.