While we are arguing about what Socialism is and ought to be about it is often forgotten that it is intended to address Capitalism and all its many, alleged, evils. Therefore in order to know Socialism we have to know Capitalism.
But what is it? At this stage we come back to Star Trek, that basic guide to philosophy etc. that has informed most of us. The answer is perhaps "It is life Jim, but not as we know it." Except that the line was never used.
A useful quide to this is in the link which suggests several lines that related to this question and the answers are not all quite the same. On the one hand it depends what you are looking at and on the other it depends what you think, repeat think, you see.
Given that so much of what we think of as capital today is in fact pieces or paper or digital figures mostly created and representing only themselves we could be in for some surprises. One is that the globalisation dependent on capitalism and on which capitalism is said to depend may not be working as we think.
Globalisation may have its limits according to this article in This Finite World and there is a case that it might have a peak and that is now about to be reached. From here it is all downhill however much increased population and the peoples of the world might demand from their governors.
If history is any guide long major down turns do not go equally for all and are more rapid in some places and less so than others. This is the cue for and cause of many troubles, conflicts and wars. Prolonged declines make matters worse. If our media and leaders do not understand this or do not want to this does not help.
Beam me down Scotty.