The component diagram's main purpose is to show the structural relationships between the components of a system. In addition, component diagrams are useful communication tools for various groups. In creating a component diagram, there are different notations that can be used to show the different relationship of each component within the system. The component diagram notation set now makes it one of the easiest UML diagrams to draw:
* COMPONENT
A component can be shown as a rectangle with a keyword <<component>>, component name, and the visual stereotype or component icon. * INTERFACE
A component defines its behaviour in terms of provided and required interfaces. An interface is the definition of a collection of one one or moore. It provides only the operations but not the implementation. Normally, an interface may be shown using a rectangle symbol with a reyword <<interface>>. An interface ca be used as a provided interface(a) or required interface(b):
A provided interface characterize services that the component offers to its environment. And it is modeled using a ball, labelled with the name, attached by a solid line to the component.. It is also known as a lollipop interface. While a required interface characterize services that the component expects from its environment. It is modeled modeled using a socket, labelled with the name, attached by a solid line to the component.
Where two components/classes provide and require the same interface, these two notations may be combined, like shown above. The ball-and-socket notation hint at that interface in quiestion serves to mediate interactions between the two components. If an interface is shown using the rectangle symbol, we can use an alternative notation, using dependency arrows.
In a system comtext where there are multiple components that require or provide a particular interface, a notation abstraction can be used thath combines