A deployment server is the Splunk system that distributes apps, configurations, and other assets to universal or heavy forwarders, and in some environments, other Splunk Enterprise instances. You'll typically use the deployment server just to distribute and maintain the inputs.conf, outputs.conf, and possibly a number of other configuration files and apps on all your universal forwarders so that you don't have to maintain them on a server-by-server basis manually.
It is not a requirement that you use a deployment server; you can use an external tool such as Windows System Center Configuration Manager, or chef, puppet, or salt if your deployment runs on *nix servers. However, a deployment server is the fastest and most native way to get apps and configurations deployed to your Splunk universal forwarders.
Again, the most typical use of...
