It is in the interest of some people (such as “anarcho-capitalists”) to confuse property and possession, and to claim that everyone is actually advocating a property system. They wish to hide the injustices of property theory under the pretense that we have no choice but to have property rights. Db0 discusses this unfortunate tendancy.
You see, it does not really matter what we call the various systems of ownership, we could call them blue and purple bananas for all the good it will do us. The important thing is that we understand the same concepts. That the socialist criticize the ownership system which facilitates and promotes wage-slavery, rent and usury and promote one which makes that systematically impossible. That this is not a discussion on how we’re going to enforce it (voluntarily or coercively) but on simply which system we ought to prefer.
To simply take your own or what you assume are the “right” definition of the word ‘property’ and superimpose it onto socialist critique, is simple a recipe for strawmen fallacies. Perhaps you have the most popular definition. Perhaps you have the proper or more the most clear. Perhaps not. The important thing to remember, as Proudhon pointed out in the past, is that if you’re going to call all types of ownership “property” then you really need a way to distinguish between possession and “sticky property”. He suggested to call the later the more appropriate name of “theft” of course but I doubt the propertarians will agree on that.