A yo-yo is a popular toy consisting of two discs connected by an axle, with a string wound around it. When the yo-yo is thrown down, it unwinds and then returns to the hand when pulled back. This simple mechanism allows for various tricks and styles of play, making it enjoyable for people of all ages. The history of the yo-yo dates back thousands of years, with origins in ancient Greece and China. It has evolved over time, with modern versions made from materials like plastic and metal. Yo-yos are often used in competitions, showcasing skill and creativity in performing tricks.