Neo-liberalism is an ideology that advocates and a process that occurs by capital (and its agents) to redraw the frontier of economic and political control back in favour of itself in order to resolve the crisis of capitalist profitability. What is most distinctive about neo-liberalism, compared to liberalism, is its willingness and ability to use the state to deregulate the economy whilst also increasingly regulating labour in order to create conductive conditions for the return of capitalist profitability. Hence, Wikipedia says:

Neo-liberalism refers primarily to the 20th-century resurgence of 19th-century ideas associated with laissez-faire economic liberalism. Those ideas include economic liberalization policies such as privatization, austerity, deregulation, free trade and reductions in government spending in order to increase the role of the private sector in the economy and society. These market-based ideas and the policies they inspired constitute a paradigm shift away from the post-war Keynesian consensus which lasted from 1945 to 1980.