This word is super unhelpful in politics because everybody has different ideas on what it means. When some Americans hear that Bernie Sanders is a socialist, they picture the Soviet Union.
Bernie Sanders calls himself a “democratic socialist,” which would distinguish his ideology from the totalitarian, non-democratic form of government practiced in the USSR. However, he’s not really a democratic socialist either. He’s actually a “social democrat.” Social democracy exists within a democratic, capitalist system and includes measures to promote social justice and a strong safety net. There may be some elements of wealth or income redistribution but basically it’s a robust welfare state. Those of you from Canada or Europe are probably a lot more familiar with social democrats than I am.
The big difference between democratic socialism and social democracy, as I understand it, is that social democrats aren’t trying to seize the means of production. In other words, businesses can remain privately owned, rather than state-owned. Honestly it would probably be better if Sanders didn’t call himself a socialist.
Here’s wikipedia on the two philosophies: