A Dependency signifies a supplier/client relationship between model elements where the modification of a supplier may impact the client – in other words, that the semantics of the client is not complete without the supplier.
To model a Dependency between two Classifiers in UML, you create a Dependency Node of the appropriate type (Dependency, Usage, Abstraction, or Realization), and then create the Dependency Node to Client relationship definition and the Dependency Node to Supplier definition, respectively.
Relates
The Dependency Node to Client relationship can relate these items: