What is the difference between social liberalism and neo-classical liberalism?

Both are forms of liberalism and extoll a republican government answerable to its citizens as well as some implementation of capitalism, but differ in the extent to which they support pure laissez-faire capitalism. Social liberalism is what many in the USA refer to as simply "liberalism": it supports government intervention in the economy for purposes of providing social services such as education, medical care, and assistance with food or shelter for the poor. Neo-classical liberalism (aka libertarianism, neoliberalism), on the other hand, is an extreme laissez-faire ideology that rejects government interference in the economy, and relies upon private businesses and the free market to provide any desired social services. Often, neoliberals and conservatives share this economic perspective, but differ in their social policies; neoliberals tend to disapprove of the conservative support of gay marriage bans, drug prohibition, and, often, the imposition of Christian religious values. One could also fairly accurately distinguish these two philosophies by their economic theories: social liberalism values Keynesian economics, neo-classical liberalism values Austrian economics.