I had to deal with a really poor education during my school years, so, for that matter, I have for a long time been (re)teaching myself some of the subjects I (didn’t) learn at school. One of those involves economic ideologies/systems like communism or capitalism.
I have a vague idea of what each one is about thanks to common sense, but it is kind of a shame being an adult and not knowing much about them.
So… where do I start from?
Worth keeping in mind that these ideologies each have multiple self-definitions (the ideal with which they describe themselves) as well as a set of definitions from the perspective of each other ideology. Tack on semantic drift (words changing meaning over time, or growing different meanings in different contexts) and it can start to feel hopelessly complicated. And they each offer different ways of understanding the world and history, so on top of all the aforementioned complexity, they also interpret historical events and real-world applications of each ideology differently. So learning about them is a process where your understanding slowly moves from abstract to concrete by getting rough definitions then tempering them with seemingly contradictory definitions, over time building a network of understanding that includes the contexts of each perspective.
My perspective is largely coming from a communist ideology fyi. But here’s a quick rundown.
Capitalism is a system in which a class of owners leverage their ownership of productive assets to engage in non-equal exchange with the un-owning classes, most notably the exchange of labor value for a fraction of the products of said labor value. It necessitates a large government to enforce these hierarchies of ownership and exclusion. (Classical) liberalism is the ideology of capitalism. Conservatism is generally a subset of liberalism. It’s the culturally dominant ideology now, so most of what you see and read will come from this perspective, explicitly or not.
Communism is a theoretical system in which class tensions have resolved themselves. No one knows what it’ll look like, it’s explicitly a theoretical ideal. Communism as an ideology is advocating for the interests of the working class against the owning class. A country that calls itself communist would probably be doing so in reference to the ideology, rather than claiming it has achieved communism.
Socialism as an ideology can be synonymous with communism, although there are subsets of liberalism that have taken on the word to mean capitalism with welfare and regulations. Socialism as a system is the interim stage between capitalism and communism, the point where workers have seized control of the state and means of production and now have a strong influence over how class tensions develop.
This is a good summary. To simplify/describe it slightly differently, the definitions of capitalism and communism and socialism decribe the relationships between workers and the value of the work that they do.
Under capitalism, owners own the business and employ workers who are paid wages. The value of the products or services that the workers make is more than they are paid - and this extra value produced (profit) goes back to the owner. Thus, you end up with two classes of people, the workers/wage laborers (proletariat in communist jargon), and the owners (bourgeoisie in communist jargon).
In socialism, the workers own the businesses, and so the profit goes back to them instead of to the non-working owners. Thus in socialism, there is only the one class, the workers, and the bourgeoisie class has been removed.
This is extremely simplified, but I think describes the overall work and value relationships under the two systems.
I hope this helps too.