The index=_internal component=DC* host=<uf> search will show all deployment client messages from the universal forwarder. The component field indicates the type of Splunk component that generated the message, and the host field indicates the host name of the machine that sent the message. The index=_audit component=DC* host=<uf> search will not return any results, because the deployment client messages are not stored in the _audit index. The index=_internal component=DS* host=<ds> search will show the deployment server messages from the deployment server, not the client. The index=_audit component=DS* host=<ds> search will also not return any results, for the same reason as above

In the context of splunkd.log events written to the _internal index, the field that identifies the specific log channel is the "channel" field. This information is confirmed by the Splunk Common Information Model (CIM) documentation, where "channel" is listed as a field name associated with Splunk Audit Logs.

Explanation/Reference: https://answers.splunk.com/answers/237859/can-i-delete-all-data-from-a-kv-store-at-once.html

Explanation
The Splunk Universal Forwarder is the only Splunk Enterprise offering that has its own license. The Splunk Universal Forwarder license allows the forwarder to send data to any Splunk Enterprise or Splunk Cloud instance without consuming any license quota. The Splunk Heavy Forwarder does not have its own license, but rather consumes the license quota of the Splunk Enterprise or Splunk Cloud instance that it sends data to.
The Splunk Cloud Forwarder and the Splunk Forwarder Management are not separate Splunk Enterprise offerings, but rather features of the Splunk Cloud service. For more information, see [About forwarder licensing] in the Splunk documentation.