The 100 exists in a future where the humans abandoned Earth 97 years before.
When resources on the Ark space station become scarce, 100 kids are sent to Earth to see if it will sustain human life.
The 100 Season 1 Episode 1 introduces the cramped quarters and strict rules of the Ark and the open environment with no rules on Earth.
Life is challenging both on the Ark and on Earth. Watch The 100 online now to make your pick on which would be worse.