Okay kiddo, so you know how grown-ups sometimes smoke things like cigarettes or cigars? Well, some grown-ups also like to smoke a little bit of a special plant called marijuana.
Instead of smoking a lot of it at once, they use something called a one hitter. It's a little tube like a straw, but it's made of metal or glass so it doesn't burn.
They put a tiny bit of the marijuana into the end of the one hitter that looks like a bowl. Then they hold the other end up to their mouth and light the marijuana with a lighter. They breathe in the smoke and it makes them feel a little different than usual.
Some people like to use a one hitter because it's easier to control how much they're smoking and they don't want to smoke a whole lot at once. Plus, it's small and easy to carry around.
But remember, smoking anything is not good for your health and it's only for grown-ups to do. So don't try it until you're older and even then, it's best not to do it at all.