A property is a characteristic of an object; for example, a red object is said to have the property of redness. The cited article, which is where the Wikipedia term mathematical property leads and which is written from philosophy and logic, says the property may be considered a form of object in its own right, able to possess other properties, and that a property differs from individual objects in that it may be instantiated, and often in more than one object. It is the general notion behind the properties, such as commutativity or compactness, that mathematical objects are said to have. Objects recorded in the atlas as mathematical properties are grouped under this concept.