(1) A labeled container in which to store a value. Properties can specify characteristics of objects. (2) In KVC, any of the three kinds of object values that KVC can access: attributes, to-one relationships, and to-many relationships. (3) In a scripting definition file, a characteristic of a class that has a single value and is identified by a label. Synonymous with a key-value coding (KVC) attribute or to-one relationship. A window’s name property would be equivalent to a KVC attribute, while its document property would be equivalent to a KVC to-one relationship. (3) In Core Audio, a key-value pair that declares an attribute or behavior, such as audio data stream format or latency. Each property has an associated data type to hold its value. Properties are typically non-time-varying and not directly settable by the user. Compare parameter. (4) In Entity-Relationship modeling, an attribute or relationship. See also attribute, relationship