Citizen Specialization
Job Specialization
Citizens on a Core World will apply a small proportion of all of their statistics to the world's Planetary Output as a product modifier, which represents the work they are doing and contributing towards the smooth running of the planet. Each Citizen contribute a little towards Research, Manufacturing, Food, Wealth and Cultural production, and so the more Citizens on a planet, the better.
Citizens can also be specialized into a specific employment role known as a Job, which focuses them on one particular output type, and applying a larger proportion of that specific statistic to the related output at the expense of a reduced overall output across the rest of the output types.
Certain Jobs are locked behind Technologies, while others are tied to Civilization Abilities or Ideological Traits, and generally speaking, the further into the game that the player progresses, the more and better Jobs will become available to their Citizens.