A truck sleeper is like a cozy little bed in the back of a big truck for the driver to sleep in when they're taking long trips. It's like a small bedroom that has everything the driver needs to be comfy and get a good night's sleep. There's usually a bed, a pillow, blankets, and even curtains or blinds to block out the light. And sometimes there's a little TV, a mini-fridge, and even a bathroom sink! So when the driver gets tired on a long trip, they can just crawl back into their sleeper, take a nap, and wake up refreshed and ready to keep driving.