You can create relation extensions to define relationships between the objects in the vSphere environment and organize the objects in groups under categorized tabs.
The vSphere objects that make up the virtual infrastructure are organized as a graph of related objects. Each type of vSphere object maintains parent-child relationships with adjacent objects. For example, a host object can have several related virtual machine objects as children, while many host objects might have a single cluster object as a parent. The relationships between vSphere objects are reflected in different places in the vSphere Web Client GUI, including the object navigator and the categorized tabs for relations in an object workspaceon the Related Objects tab in an object workspace. The object navigator and object workspaces can display the related items for a vSphere object, such as the virtual machine objects associated with a given host object.
The vSphere Web Client uses relation extensions to represent the relationships between objects. A relation extension defines a relationship between a vSphere object and any other objects in the hierarchy of the virtual infrastructure. Certain extensions, such as some object navigator nodes and object list views, reference relation extensions to obtain their information. You can create relation extensions to add new relationships between vSphere objects in your vSphere environment, and to have other areas of the vSphere Web Client reflect those relationships.
You create a relation extension when you want the user to receive information about other vSphere or custom objects, either in a list view or in the object navigator, when they select or focus on a given vSphere or custom object. For example, if you created Chassis object type, it might contain one or more host objects. You can create a relation extension for the Chassis object so that information about any related host objects also appears in the object workspace or object navigator when the user selects a Chassis object.
You can add a relation extension to the vSphere Web Client to create a new relationship between a given type vSphere object and any other object type in the virtual infrastructure hierarchy. If you add a new type of object to the vSphere environment, you must create a relation extension to place your new object in the graph of vSphere objects, and to populate the Related Items views.
You can also create a relation extension for two existing vSphere objects that do not have an existing relationship. You might create such a relation to take advantage of the Related Items views in the object navigator and object workspaces for those objects, or if you created an object collection node for an existing object in the object navigator.