structural:reformatting
As a name for political parties

Many socialist parties in several countries have been, or are called Social Democratic. In the 19th century, social democrat was a broad catch-all for international socialists owing their primary ideological allegiance to Lassalle or Marx, in contrast to those advocating various forms of utopian socialism. Many parties in this era described themselves as Social Democrats, including the General German Workers' Association and the Social Democratic Workers' Party of Germany, which merged to form the Social Democratic Party of Germany, the Social Democratic Federation in Britain, and the Russian Social Democratic Labour Party. Social Democrat continued to be used in this context until the Bolshevik Revolution of October 1917, when Communist came into vogue for individuals and organizations espousing a revolutionary road to socialism.

In the 20th century, the term came to be associated with the positions of the German and Swedish parties. The first advocated revisionist Marxism, while the second advocated a comprehensive welfare state. By the 21st century, parties advocating social democracy include Labour, Left, and some Green parties. Most social democratic parties consider themselves democratic socialists and are categorized as socialists. They continue to reference socialism, either as a post-capitalist order or, in more ethical terms, as a just society, described as representing democratic socialism, without any explicit reference to the economic system or its structure. Parties such as the Social Democratic Party of Germany and the Swedish Social Democratic Party describe their goal as developing democratic socialism, with social democracy as the principle of action. In the 21st century, European social democratic parties represent the centre-left and most are part of the Party of European Socialists, while democratic socialist parties are to their left within the Party of the European Left. Many of those social democratic parties are members of the Socialist International, including several democratic socialist parties, whose Frankfurt Declaration declares the goal of developing democratic socialism. Others are also part of the Progressive Alliance, founded in 2013 by most contemporary or former member parties of the Socialist International.