Constructive dismissal is when you have a job but your boss treats you really badly, and makes you feel like you have no choice but to quit. It's not like they actually fired you, but they make the situation so bad that you feel like you don't have any other option. It's like when a grown-up bullies a kid on the playground until the kid decides to go home instead of playing anymore. It's not fair, and it's not nice, but unfortunately it happens sometimes in grown-up jobs too.