Barley sugar is a type of candy that people have been eating for a really, really long time! It's made by boiling sugar syrup until it gets thick, and then adding barley sugar flavoring to it. Some people say it tastes like honey or molasses, or like a warm, toasty flavor.
Once the barley sugar mixture is ready, it's poured into little molds that are shaped like sticks or twists. As it cools, the mixture hardens and becomes solid, so you can hold it or put it in your pocket without it getting messy.
Barley sugar was really popular with sailors a long time ago, because it didn't melt in hot weather and it helped prevent seasickness. Nowadays, people still eat barley sugar as a special treat or as a way to soothe a sore throat. Some people even like to suck on barley sugar while they're studying or working because it helps them concentrate!
So in summary, barley sugar is a yummy candy that's made by boiling sugar and adding flavoring, and then molding it into little sticks or twists that people can eat as a snack or use to soothe a sore throat. And it's been around for a very long time!