A prison is a place where criminals and people waiting for trials are locked up. If you’ve been cooped up in the house, you might feel like you’re stuck inside prison walls. But if you’re not, go outside already.
A person who's been sentenced to time in prison is called a prisoner. Prisons vary, but usually prisoners are confined to a small cell, with time spent in large groups for eating, working, and exercise. If you feel like you're stuck in a place or a situation, you might call that prison: "I can't wait to go home — this summer camp is like a prison!" The Latin root is prension, "laying hold of."