UML Weekend Crash Course™ - To Parent Directory

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Glossary
activation
The execution of an operation on an object, or another call to an object to initiate a behavior
on that object. An activation is shown as a thick vertical object lifeline segment on the
Sequence diagram. For more information see Session 16.
active object
An object in control of a thread or process that can initiate control activity. In a Sequence
diagram, this is identified by adding an activation bar to the object lifeline, usually for the
full length of the timeline. In an Object diagram, this is signified by making the object
icon bold.
activity
Processing that an object performs while it is in a specific state. An activity is typically
non-atomic (that is, it may be composed of any number of subtasks). Because an activity
does not cause the object to change states, it may be interrupted. Contrast this with
actions. For more information see Session 14. See also action.
actor
A person, system, or device that interacts with the system in a Use Case diagram. For more
information see Session 6.
aggregation
A type of association in which one object represents a collection, assembly, or configuration
of other objects such that the assembly is greater than the sum of its parts. Aggregation is
characterized by focus of control in the one object representing the “whole,” propagation
from the “whole” object to its parts, and the fact that the entire assembly functions as a
single, coordinated unit. For more information see Session 11. See also composition.
ancestor
Any class that resides higher than the reference class in a generalization hierarchy. See also
superclass, subclass, and generalization.
association
A relationship between classes that specifies the type of links that may be created between
objects of the associated classes. For more information see Session 10. See also link.
association class
Information about an association that has been abstracted into its own class. For more
information see Session 10.
asynchronous event or action
A type of message that does not require a response and does not require the sending object
to wait. For more information see Session 16.
attribute
A class member used to define a unit of information owned by the containing class, including
such details as type and domain of values. For more information see Session 9.