Topics are a critical part of iService. They are used to organize answers within the iService knowledge base and to create message queues for routing questions to customer support representatives. Topics are organized into a hierarchical topic tree as "branches" or topic categories that can be publicly visible or private. You can learn more about topics in the Understanding Topics
Because interactions are associated with topics, deleted topics are not removed from the database. Their status is marked as deleted and they're removed from your view of the topic tree. You can display deleted topics and restore them by changing their visibility to public or private.
The Show Deleted Topics toggle
The Topic List
Creating a New Topic
Topic Details Panel