In some places like the United Kingdom, people sometimes use a unit of measurement called a “stone” to talk about how much someone or something weighs. A stone is a little bit like a pound, which you might already know about.
But instead of 1 pound, a stone is equal to 14 pounds. So if you had 14 small toy cars that each weighed 1 pound, you could put them all together and say they weighed 1 stone.
It’s just another way people measure weight, kind of like how we can use inches or centimeters to measure how tall someone is.