The universal forwarder and the light forwarder are not the same thing. The full documentation topic that explains the differences between the types of forwarders is Types of forwarders in the Distributed Deployment Manual. The universal forwarder is a separate download; it is a streamlined version of Splunk that only contains the components necessary to forward data to receivers. The heavy and light forwarders are both full Splunk instances. A heavy forwarder can index data locally, but that capability is turned off by default. If you are using the indexing feature of a heavy forwarder, you must have an Enterprise license and the heavy forwarder must be part of your Enterprise license stack. It does not need a separate license. See the Forwarder license topic in the Admin Manual.
In splunk , we generally use two type Forwarder:
About license in enterprise environment : you can get here more details