A unicycle is a type of vehicle that has only one wheel, and it is typically ridden by balancing on it while pedaling. It has a simple design, usually consisting of a single wheel, pedals, and a seat. Unicycles are often used for performing tricks or stunts, and they require a good sense of balance and coordination to ride. They are popular in circus acts and as a form of personal transportation for some people. Unicycles are known for being compact and lightweight, making them easy to carry or store.