Социализм - это в первую очередь общественная (государственная) собственность на средства производства. Ни соц-дем, ни соц-либ это не предполагают. А вот демсоц предполагает
Social democracy originated as an ideology within the socialist and labour movement, whose goal at different times has been a social revolution to move away from capitalism to a post-capitalist economy such as socialism, a peaceful revolution as in evolutionary socialism, or the establishment and support of a welfare state. Its origins lie in 1860s Germany as a form of revolutionary socialism associated with orthodox Marxism.