There are multiple definitions. some define a system with government regulation of production but a free market and elections. Sanders views seem similar to the European form of socialism. From the preamble of European socialist party (PES, 2011)...
Market forces, driven by finance and greed, are annexing huge amounts of power from democratic control. These forces serve the interests of a privileged few. Conservatives and neo-liberals, have deepened economic, geographic and social inequalities, promoting a system of short-termism, easy profits and loose rules that has led to the worst crisis in modern times. We reject the politics of pessimism that claim that nothing can be done. We reject the language of hate that makes people, and whole communities, scapegoats for the ills in societies. Instead, we work to build inclusive societies and a better future for all. We need a new progressive global agenda to enable the fruits of globalization to benefit all. This is a matter of political choice and responsibility.