Conkers are the seeds of the horse chestnut tree, scientifically known as Aesculus hippocastanum. They are typically round, shiny, and brown, encased in a spiky green shell. Conkers are commonly found in autumn when the shells split open, revealing the seeds inside. While they are often associated with children's games, they are not edible for humans. The game of conkers involves threading a conker onto a string and taking turns to strike opponents' conkers until one breaks. This traditional game is popular in the United Kingdom and has been played for generations. Conkers are also known for their use in folklore and as a natural remedy for various ailments.