It is not the same thing as anarchocapitalism, because anarchocapitalism is a raging oxymoron and conceptually self-annihilating.
Corporations and corporate power structures are no less a threat to liberty than political power structures. Because capital is social power, eh? Capital exhibits all of the gravitic tendencies of human power to concentrate itself, creates all of the same wild imbalances and injustices, and is ultimately as much threat to freedom and human dignity as any other form of collective power.
Wealth has always worked this way, which is why my moral teacher spent a remarkably large amount of time challenging the ethics of capital in his day. Profit maximization and the relentless focus on the accrual of capital were, for him, fundamentally suspect and dangerous to our integrity as persons.
At best, wealth represented a system that needed to be subverted and used slyly against itself.
At worst, Mammon was the heart of our failure. It is the system that enslaves us.
Which, again, is why it is so peculiar seeing those who are nominally libertarian so enthralled by the power dynamics of capital. It is no less a danger to liberty than concentrations of political power. Assuming that the accrual of socially mediated proxies for ownership and control somehow makes one more "free" is absurd.
Freedom, for the libertarian, is an essential state of being, a fundamental aspect of sentience and personhood. It is an inalienable right. It will always stand independent from imagined structural frameworks, be they legal or economic.