system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Socialism

And specifically, not not exclusively, the difference between socialism and communism.
gpt
Socialism and communism are basically two different takes on a very similar idea. At their heart is a belief that the capitalist world is an unfair place where some people have more than others and that those with more take advantage of the needy. In order to make the world a less unfair place, the state needs to step in and redistribute wealth from the rich to the poor. How they go about this and to what extent is where they differ.

For a socialist, the state is there to even out the excesses of capitalism and it tends to do this by imposing progressive taxation (so the more you earn, the higher percentage of tax you pay) whilst also providing services that the poor cannot afford (like health care). Sometimes it may involve 'nationalising' certain industries (so the state taking control of things it thinks to be very important to the general welfare of the population such as water, electric and gas) but how far they go with this depends on how far to the left a certain government is. The big thing is that socialism can coexist with democracy and doesn't require the use of force. For example, many Western European governments have been 'socialist' for periods of time and have been voted in and out of power over time. There was never a need for a revolution to install them. Also, socialism tends to respect the fundamental civil liberties that we tend associate with democracy (freedom of speech, freedom of belief, etc, etc) and can coexist with capitalism providing it can round of its harder edges.

Communism is still about making the world more equal but its methods are very different. From a communist point of view, the people who hold power in the world (the bourgeois) are not going to let go of it without a fight so the oppressed (the proletariat) will have to seize it, whether by violent or non-violent methods. Once that has happened Communists believe that there is a danger that power will be wrestled back from them so they see need for a period of 'a dictatorship of the proletariat'. This is where the communist party assumes complete control of the state in order to protect the revolution. That means nationalising pretty much everything, the suspension of democracy as we know it and the necessity of a police state. In theory, this should last for a certain amount of time until the nation as a whole see how wonderful an equal society is and start to live there lives voluntarily within the parameters of a communist system. At this point the, the state would whither away to the point where there is no state anymore. The problem is that no-one ever seems to have made the transition form dictatorship to utopia and you tend to end up with a totalitarian regime that becomes focused on extending/protecting its power.