To an American young liberal who votes for Bernie Sanders, socialism = that things they have in Nordic countries.
Socialism is usually described by socialists/Marxists as an early stage of communism, with the goal being the abolishment of private property and workers owning the means of production. If an American uses socialism positively, they almost certainly mean social democracy, which is heavily regulated capitalism with social safety nets.
I can't find it now, but I remember there was a survey that asked Democrat and Republican voters to list countries they considered socialist, and Democrats listed the Nordic countries, and Republicans listed China, Venezuela, and Russia (???).