Knew this would be about FF13 by just seeing the name. I've never seen the problem with l'Cie, fal'Cie, etc. To me it's literally no different than Jedi, Sith, Dwemer, etc. You learn about it as you learn about the world/universe. Also, they explain what they are in the first four pages of the manual that came with your game.
Cocoona utopia in the sky.
Its inhabitants believed their world a paradise. Under the Sanctums rule, Cocoon had long known peace and prosperity.
Mankind was blessed by its protectors, the benevolent falCie, and believed that tranquil days would continue forever.
Their tranquility was shattered with the discovery of one hostile falCie.
The moment that falCie from Pulsethe feared and detested lowerworldawoke from its slumber, peace on Cocoon came to an end.
FalCie curse humans, turning them into magic-wielding servants. They become lCiechosen of the falCie.
Those branded with the mark of a lCie carry the burden of either fulfilling their Focus or facing a fate harsher than death itself.
A prayer for redemption. A wish to protect the world. A promise to challenge destiny.
After thirteen days of fates intertwined, the battle begins.