Socialism
In social democracies, some services and industries are subsidized (given subsidy money to help them run even if they are failing), partly controlled by the government, or both. For example, education, health care, housing, utility companies and public transportation are some industries that might be owned/supported by the government in a social democracy. For the most part, people working in these industries are paid by the government, with money paid by the people as taxes. A strong Welfare system is key to social democracy.