This was an issue I struggled with a bit at first, and while the Splunk team is very excellent, there own perspective is not always intuitive with respect to naming and function.
Splunk DOCs describe the following about the deployment server, in particular the deployment clients have a defined deployment server that manages the configurations that are pushed out to it see the following:
Plan a deployment - Splunk Documentation
"
Deployment server and clusters
You cannot use the deployment server to update indexer cluster peer nodes or search head cluster members.
Indexer clusters
Do not use deployment server or forwarder management to manage configuration files across peer nodes (indexers) in an indexer cluster. Instead, use the configuration bundle method. You can, however, use the deployment server to distribute updates to the manager node, which then uses the configuration bundle method to distribute them to the peer nodes. See "Update common peer configurations" in the Managing Indexers and Clusters of Indexers manual.
Search head clusters
Do not use deployment server to update search head cluster members.
The deployment server is not supported as a means to distribute configurations or apps to cluster members. To distribute configurations across the set of members, you must use the search head cluster deployer. See "Use the deployer to distribute apps and configuration updates" in the Distributed Search manual."
The reference for respective configuring is here:
Deploying Apps:
Use the deployer to distribute apps and configuration updates - Splunk Documentation
(see this section: https://docs.splunk.com/Documentation/Splunk/latest/DistSearch/PropagateSHCconfigurationchanges#Depl...)
By contrast, apps and configurations are managed by the deployment server, here:
Create deployment apps - Splunk Documentation
