system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 the difference between Existentialism and Nihilism. 

What exactly is the difference? Is it a grander sense of optimism vs. pessimism applied to a basic concept that led to these two philosophies or are they entirely different?
gpt
Nihilists would say that there is no objective truth in the world and therefore there can be no "meaning" or "purpose" in life. Existentialists accept that there is no objective truth, but instead of saying that there is no purpose and no point, they make up their own goal/purpose to do whatever the hell they want. Existentialists are generally more fun at parties.