Hi
The Type Category in WorkItem->Types & Attributes is an implementation detail of how we treat work item types. Currently, All types in the same type category have the same set of custom attributes, the same workflow and might have the same set of required attributes. The existence of such a Type Category is mostly due to historical reason. We are discussing to remove that concept in one of the next versions. To not get confused, you can treat Type Categories as a container for work item types. Type Categories are only used when customizing work items.

The Categories available form the Work Item Categories tab are the structure to were the users file their work items against (this can e.g. be components and sub-components).

Regards

Marcel
Jazz Work Item team