The following is from the introduction to the wiki article. See it for much more detail.
Democratic socialism is a political ideology advocating a democratic political system alongside a socialist economic system, involving a combination of political democracy with social ownership of the means of production. Sometimes used synonymously with “socialism”, the adjective “democratic” is added to distinguish democratic socialism from Marxism–Leninism.
Democratic socialism is distinguished from both the Soviet model of centralized socialism and from social democracy. This distinction arose from the authoritarian form of government that emerged in the Soviet Union in the 20th century under the banner of socialism.
Democratic socialism rejects the social democratic view of reform through state intervention within capitalism, seeing capitalism as incompatible with the democratic values of freedom, equality and solidarity. From this perspective, democratic socialists believe that the issues inherent to capitalism can only be solved by a transition from capitalism to socialism – by superseding private property with some form of social ownership; and that any attempt to address the economic contradictions of capitalism through reforms will only cause problems to emerge elsewhere in the economy. However, “democratic socialism” is sometimes used as a synonym for social democracy, where “social democracy” refers to support for political democracy, regulation of the economy, and a welfare state.
There is no exact definition of democratic socialism. Some forms of democratic socialism overlap with social democracy, while many forms reject social democratic reformism in favor of more transformative methods, while some forms overlap with Revolutionary Socialism. The “democratic” element may refer to extending principles of democracy in the economy (such as through cooperatives or workplace democracy), or it may refer to support for a multi-party parliamentary democracy.