Severance is about an office in which to work there, the "outtie" who is not at work gets a procedure done where they forget what they do at work every day for 8 hours. The "Innie" does not know anything about their outtie's life and only experiences life when they are at work.
But the company is terrifying and I have theories about whether or not the administration goes through severance, and the "outtie's" mostly live in company housing so they can be spied on. It's kind of terrifying.