In
modern philosophy and
mathematics, a
property is a characteristic of an
object; a red object is said to have the property of redness. The property may be considered a form of object in its own right, able to possess other properties. A property however differs from individual objects in that it may be
instantiated, and often in more than one thing. It differs from the logical/mathematical concept of
class by not having any concept of
extensionality, and from the philosophical concept of
class in that a property is considered to be distinct from the objects which possess it. Understanding how different individual entities (or particulars) can in some sense have some of the same properties is the basis of the
problem of universals. The terms
attribute and
quality have similar meanings.