Conlangs are languages that have been "artificially created".
I was interested in this stuff years ago and suddenly decided to make a list about it, so "I took the time to do a little research" as Pastor Martin Ssempa would say.
Some of these are international auxiliary languages, which means a language that's meant for communication between people from different nations who don't share a common language.

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1. Klingon
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This is certainly one of the most well-known ones.