"Neo-liberalism" is a set of economic policies that have become widespread during the last 25 years or so. Although the word is rarely heard in the United States, you can clearly see the effects of neo-liberalism here as the rich grow richer and the poor grow poorer.
"Liberalism" can refer to political, economic, or even religious ideas. In the U.S. political liberalism has been a strategy to prevent social conflict. It is presented to poor and working people as progressive compared to conservative or Rightwing. Economic liberalism is different. Conservative politicians who say they hate "liberals" -- meaning the political type -- have no real problem with economic liberalism, including neoliberalism.
"Neo" means we are talking about a new kind of liberalism. So what was the old kind? The liberal school of economics became famous in Europe when Adam Smith, an Scottish economist, published a book in 1776 called THE WEALTH OF NATIONS. He and others advocated the abolition of government intervention in economic matters. No restrictions on manufacturing, no barriers to commerce, no tariffs, he said; free trade was the best way for a nation's economy to develop. Such ideas were "liberal" in the sense of no controls. This application of individualism encouraged "free" enterprise," "free" competition -- which came to mean, free for the capitalists to make huge profits as they wished.