A plastic bottle is something that can hold liquid, like water or soda. It's made of a material called plastic, which is kind of like a super-duper strong and hard version of rubber.
The plastic is shaped into the form of a bottle by a machine, which heats up the plastic and squishes it into the shape of a bottle. Once it's cooled down, the bottle is ready to be used.
When you're done drinking what's inside the bottle, you can throw it away. But instead of putting it in the trash, it's a good idea to recycle it. That means somebody will take the plastic bottle and turn it into something new, like a chair or a backpack.
Plastic bottles are really handy because they're light and easy to carry around. But it's important to remember that they're not good for the environment if they're not recycled properly. So always try to recycle your plastic bottles whenever you can!