Merge pull request #937 from mandy-chessell/code2024

Describe brain explorers

site/docs/user-interfaces/brain-explorers/overview.md

@@ -4,5 +4,30 @@
 # Egeria Explorers
 
 
+## Open Metadata Type Explorer
+
+Egeria's [Open Metadata Types](/types) define an open format that can be used to represent any type of metadata.  Egeria defines a comprehensive starter set that can then be extended by organizations and vendors for their own use.  The formal definition for the open metadata types supplied by Egeria documented in the [Universal Modelling Language (UML)](https://en.wikipedia.org/wiki/Unified_Modeling_Language).  For example, the definitions of [an asset](/concepts/asset) is found on the [0010 Base Model](/types/0/0010-Base-Model) page.
+
+The UML diagrams have the disadvantage in that it is hard to see how the types "fit together".  The *Open Metadata Type Explorer* provides an interactive graph-based visualization of the open metadata types, linked together into a single schema.  The image below shows a screenshot of the [Referenceable](/concepts/referenceable) type.
+
+![Referenceable Open Metadata Type](referenceable-open-metadata-type.png)
+
+The nodes linked below it are:
+
+* The attribute types for *Referenceable*.  They begin with a lower case letter.
+* The entity types that inherit from *Referenceable*.  They begin with an upper case letter.
+
+The types linked to the left-hand side are relationships that link a *Referenceable* to a another element.
+
+The types linked above are either the type's super type or classifications that attach to this type.
+
+*Referenceable* has a lot of connections.  The next screenshot is after clicking on *Actor* (see model [*0110 Actors*](/types/1/0110-Actors)).
+
+![Actor Open Metadata Type](actor-open-metadata-type.png)
+
+*Actor* has three sub-types: *ActorProfile*, *PersonRole* and *UserIdentity*.  When you click on *UserIdentity*, you see it has a relationship called *ProfileIdentity*, two additional attributes called *distinguishedName* and *userId* along with a classification called *SecurityGroupMembership*.
+
+![User Identity Open Metadata Type](user-identity-open-metadata-type.png)
+
 
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