There are two types of Splunk Forwarders as below:
Universal Forwarder (UF): The Splunk agent installed on a non-Splunk system to gather data locally; it can’t parse or index data.
Heavyweight Forwarder (HWF): A full instance of Splunk with advanced functionalities.
It generally works as a remote collector, intermediate forwarder, and possible data filter, and since it parses data, it is not recommended for production systems.