Is anarcho-capitalism the same thing as libertarianism?

No, but it’s close. Just as anarcho-capitalism is a subtype of anarchism, it is also a subtype of libertarianism. Libertarianism is the belief that liberty is the primary political virtue, conjoined with the belief in capitalism. But libertarians don’t necessarily deny the legitimacy of the State as an institution — most believe that a minimal State is necessary to provide defence services. This minimal State, sometimes called “the nightwatchman State,” is a government that provides only three things: Police, courts, and defence against foreign invasion. This means that no government redistribution of wealth or regulation of the market is allowed. Anarcho-capitalists, therefore, hold the same values as minarchist libertarians, but take it to the logical conclusion: Even a minimal State is too authoritarian. If government monopoly is bad for all other services, how can it suddenly be okay for the provision of defence? In short, an anarcho-capitalist is a radical libertarian. He rejects minarchism for anarchism.