So... it does do both... but peeling back the top layer of your question...

In an ideal world... each License Holder would set up a Node to enhance the strength of the Splinterlands Network aka SPS Chain aka Splinterchain - whatever you want to call it.

The License Holder then could Stake ANY NUMBER of Licenses to their Node... and each License Copy gives them a portion of the "Reward Pool"...

However... for people like me... who are code-idiots... we bought into the concept... and want to support the strength of the system and earn Rewards...

For Peakmonsters - this helps ensure they are one of the "Top Validators" and earn the most Rewards possible... because it requires you vote for them...

So...

Peakmonsters sets up a Node for each unique Client, no different than the Client doing it themselves = Strengthen Chain by +1 Node

Client gets Rewards = Rewards x Validator Licenses (7) in my case...

Peakmonsters gets votes for Validator King or whatever... = better Rewards for them.