When you tell the forwarder which server to send data to, you basically add a new configuration stanza into an outputs.conf file behind the scenes. On the Splunk server, an inputs.conf file will contain a [splunktcp] stanza to enable receiving. The outputs.conf file on the Splunk forwarder will be located in $SPLUNK_HOME/etc/system/local, and the inputs.conf file on the Splunk server will be located in the local directory of the app you were in (the launcher app in this case) when configuring receiving.
Using forwarders to collect and forward data has many advantages. The forwarders communicate with the indexers on TCP port 9997 by default, which makes for a very simple set of firewall rules that need to be opened. Forwarders ...