Property is defined as the right to use, enjoy or possess a determinant thing, and the right to exclude others from same.
Within the conceptual framework provided by law this control is assured by the power of the law, or by power exercised under the law, and not by any separate power. However, philosophically at least, it is possible to think of property concepts outside a legal framework - though, as in the Middle Ages, a legal framework for property might well emerge.
Legal systems have evolved to cover the transactions and disputes which arise over the possession, use, transfer and disposal of property, most particularly involving contracts. Positive law to defines such rights, and a judiciary is used to adjudicate and to enforce.
In his classic text, "The Common Law", Oliver Wendell Holmes describes property as having two fundamental aspects. The first is possession, which can be defined as control over a resource based on the practical inability of another to contradict the ends of the possessor. The second is title, which is the expectation that others will recognize rights to control resource, even when it is not in possession. He elaborates the differences between these two concepts, and proposes a history of how they came to be attached to individuals, as opposed to families or entities such as the church.
According to Adam Smith, the expectation of profit from "improving ones stock of capital" rests on private property rights, and it is central capitalism that property rights encourage the property holders to develop the property, generate wealth, and efficiently allocate resources based on the operation of the market. From this evolved the modern conception of property as a right which is enforced by positive law, in the expectation that this would produce more wealth and better standards of living.
Socialism's fundamental belief is centered on a critique of this belief, stating, in effect, that the cost of defending property is higher than the returns from private property ownership. This is still a modern theory of property however, in that it argues based on superior utility of result.
Communism argues, that only collective ownership through a polity, though not necessarily a state, will assure the minimization of unequal or unjust outcomes, and that therefore all, or almost all, private property should be abolished.
Not every person, or entity, with an interest in a given piece of property may be able to exercise all of those rights. For example, as a lessee of a particular piece of property, you may not sell the property, because the tenant is only in possession, and does not have title to transfer. Similarly, while you are a lessee the owner cannot use his or her right to exclude to keep you from the property. (Or, if he or she does you may perhaps be entitled to stop paying rent or perhaps sue to regain access.)
Further, property may be held in a number of forms, e.g. joint ownership, community property, sole ownership, lease, etc. These different types of ownership may complicate an owner's ability to exercise his or her rights unilaterally. For example if two people own a single piece of land as joint tenants, then depending on the law in the jurisdiction, each may have limited recourse for the actions of the other. For example, one of the owners might sell his or her interest in the property to a stranger that the other owner does not particularly like.
Traditionally many things existed that did not legally have an owner, such as commons (land belonging to nobody in particular, but over which commoners had rights). But over centuries and millennia law in all societies has tended to develop towards reducing the number of things not having clear owners. Supporters of property rights argue that this enables better protection of scarce resources, due to the tragedy of the commons. But there are many things today which still do not have owners: ideas, seawater, the seafloor (though due to the United Nations Convention on the Law of the Sea, some of it can now be considered in some ways property), celestial bodies, land in Antarctica.
The human body is, in modern societies, considered something which cannot be the property of anyone but the person whose body it is. This is in contradistinction to the old practice in many societies of chattel slavery, which is almost universally considered unjust and illegal today.
In many ancient legal systems (e.g. early Roman law), religious sites (e.g. temples) were considered property of the God or Gods they were devoted to. However, religious pluralism makes it more convenient to have religious sites owned by the religious body that runs them.
Property requires a class distinction between owners (possessing title and the all rights of enjoyment) and non-owners (excluded from use). Generally, it is thought that humans can be owners, and non-humans can not. (There are exceptions to this. For example, in Athens, Georgia there is a tree that owns itself.)
Some societies have restrictions against ownership of property. In some, only adult men may own property. However, in other cultures (such as the Haudenosaunee), property is matrilinear and passed on from mother to daughter. In early America, slaves were prohibited from owning property.
[T]hough the earth and all inferior creatures be common to all men, yet every man has a "property" in his own "person." This nobody has any right to but himself. The "labour" of his body and the "work" of his hands, we may say, are properly his. -- John Locke
..., that being all equal and independent, no one ought to harm another in his life, health, liberty or posessions; ... -- John Locke, Civil Government (1690)
Life, faculties, production – in other words, individuality, liberty, property – this is man. And in spite of the cunning of artful political leaders, these three gifts from God precede all human legislation, and are superior to it. Life, liberty, and property do not exist because men have made laws. On the contrary, it was the fact that life, liberty, and property existed beforehand that caused men to make laws in the first place. -- Frédéric Bastiat, The Law
Communism aims to establish a state-less and property-less society, based on the principle that goods should be produced and distributed according to the principle "from each, according to his ability; to each, according to his needs".
In theater and film, properties (or "props") are objects used in a performance which are handled or manipulated by the actors. Personal properties are handled by just one actor. Functional or working properties do some sort of function, for instance produce light.