Neoliberalism is basically a new type of liberalism. The original type was developed by economists like Adam Smith in the late 1700s.
"Liberalism" can refer to political, economic, or even religious ideas. In the U.S. political liberalism has been a strategy to prevent social conflict.
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.