Property is anything that can be owned. It can be physical (houses, cars, fountain pens, guinea pigs etc.) or intellectual (copyrights, patents etc.). Usually, the ownership of a piece of property can be transferred, sold or shared. Property therefore underpins many economic transactions. Getting on the housing ladder, depositing cash in your savings account or gifting your partner a puppy are all economic events that rely on an assumption that houses, money and dogs are property which can be owned.
Most societies are pretty into property ownership. Almost all of them have property rights (although how well these are enforced varies massively). These are laws which ensure people get exclusive decision-making power over what happens with or to their property, and that the courts will go after anyone who infringes on property rights. Indeed, the “right to own property” and not “be arbitrarily deprived of [your] property” is part of the United Nations’ Universal Declaration of Human Rights.
But even in countries with a strong rule of law, these property rights are usually limited. Tax, for example, is technically the government infringing on your right to own and dispose of your money as you wish. Governments also often award themselves the right to force landowners to sell or give up their lands, usually so they can build big infrastructure projects like roads or dams on them.
Many people think some or all types of property ownership should be prevented. Animal rights groups like PETA say we shouldn’t own pets. Berliners have started a petition to force landlords with lots of properties to sell them to the state. The Abolition Movement of the 18th and 19th centuries made owning human slaves illegal in most countries (although human slavery still persists to this day). And several political ideologies, of which communism is the most famous, are centred around the idea that individuals shouldn’t own any property whatsoever.
Groups like the above usually employ one or more of the following arguments to explain their opposition to property. The first is that some things, such as animals or human beings, should belong only to themselves. The second is that some things, such as land or rivers, should belong to everybody. Indeed, environmentalists often criticize the idea that factories can pollute parts of the natural environment as long as they pay for it, because some things are simply essential to human life on this planet and therefore can’t have a price attached to them (the technical term for this is incommensurability).
The third argument against property is that ownership is fundamentally unfair, because it allows some people to hog resources at the expense of other people who may need it more. The Berliners mentioned above, for example, feel that giving anyone property rights over thousands of houses (including the right to set high rents) wrongly prioritises the landlords’ desire to make money over normal Berliners’ need to live somewhere affordable.
Of course, there are also people who think we could make the world a better place if we had more property rights. That’s borne out of the notion that when people don’t own something, they don’t care about it or have any incentive to look after it.