object | | instance: instance is used when you are talking about the role with respect to the class and object is used when talking in a more general way | | A data element in an object-oriented system, which has its own identity, belongs to a particular class, and has behaviour and properties | | in a state until an event occurs that causes it to change state | live activation while the object is performing computations in a sequence diagram | any entity to which you can associate properties and behaviour | | 2.1 - What is Object Orientation? | | instance | without reference to the data (instance variables) contained in it | a rectangle containing a colon and the underlined name of the class (optional if it is clear from the context), which may be preceded by an optional instance name in a UML instance diagram | | several different variables at the same time |