Libertarianism is a political philosophy that upholds personal liberty. Libertarianism includes diverse beliefs, all advocating minimization of the state and maximizing individual liberty and freedom.
Libertarianism originated in the philosophy of a French political philosopher who also influenced Karl Marx, Pierre-Joseph Proudhon, who famously penned the Libertarians’ motto, “Property is Theft.”
They believe that the best system of government is one in which the most people possible have the largest possible amount of input into public policy, while still recognizing certain expertise and the efficiency of delegating some decision-making, instead of the Statist method of letting the people who are best at accumulating money bribe, bully, and blackmail their way into running huge sections of the world.
Antithetical to a Libertarian's beliefs are a system that regulates its subjects activities on a minute-by-minute basis; that controls where its subjects go, what they wear, and who they talk to; that restricts online reading material in a Beijing-style manner; that has a rigid hierarchy to enforce edicts from the upper echelons and do routine surveillance of the rank and file; that denies its subjects privacy even to the point of demanding the right to examine their urine; and that punishes infractions by permanent banishment. That is why they are as a whole against corporations.