uml/deployment-diagram.md

 **Sources:** http://www.omg.org/spec/UML/2.5 (Starting at PDF page 693)
 
-# Usage Scenarios
-The **deployment diagram** is used to describe deployment relationships between artifacts and targets, i.e. which target deploys which artifact. We distinguish *instance* and *type* level deployment relationships (l-d-r) (p. 694, first paragraph). Instance l-d-r show the deployment for actual instances of nodes, e.g. 
+# Introduction / Usage Scenarios
+The **deployment diagram** is used to describe deployment relationships between *DeploymentArtifacts* and *DeploymentTargets*, i.e. which target deploys which artifact. The abstract types  *DeploymentArtifact* and *DeploymentTarget* are extended by the classes *Node* and *Artifact*. In terms of deployment diagrams, we are mostly using *Nodes*, *Artifacts* and *CommunicationPaths* and don't consider those superclasses of the so-called meta model (this holds for every other diagram type as well).
+
+We distinguish *instance* and *type* level deployment relationships (l-d-r) (p. 694, first paragraph). Instance l-d-r show the deployment for actual instances of nodes, hence one shall use the common notation *"instance : type"* for all targets and artifacts.  e.g. the server called *node1* uses the instance *tomcat
 
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