What does socialism mean to you?

I don't get the fear around socialism. Maybe I don't understand what it means?

To me, the NHS is socialism, in America it's described as socialised medicine and is a thing of terror.
To me, Scandinavian countries are socialist, they don't look like terrible places to me.
I think socialism means high taxes (is that the worry?) with better public services provided my the state and some state ownership of essential services that are also natural monopolies, like post delivery.

Willing to be shown the error of my ways and why I should be really afraid or that I've got the whole thing completely wrong and none of the above is socialism.