What Does Fairness in AI Mean?

It's not every day that the musings of a 4-year-old echo the conversations of the world's leading technologists--but that's precisely the situation in which I recently found myself while driving my daughter home from day care. "Mama, that's not fair," she declared. Nothing that seemed to involve fairness had triggered her assertion, so I was a little taken aback. She'd been trying out different retorts lately to find the best ways to show her displeasure, but this was the first time she'd used the term "fair." Unsure how to proceed, I waited a second--and sure enough, she followed up by asking, "What does'fair' mean?"