I just bought a unicycle, a vehicle that touches down with just the one wheel.
I have ridden a unicycle. It looks so hard to do.
It is not easy.  I wanted one after watching the pros at circuses, festivals and street performers.
Oh that must have been pretty cool. Who invented the unicycle?
There were two patents for them published.  One in 1869 and one in 1881
Would there happen to be different types of unicycles?
Just like everything, there are varieties.  They even created off road unicycles in the 1980s.  Those guys are nuts!
Do the circus performers and pros do tricks on the unicycles?
Unicycle trials
Unicycle trials is a form of unicycling which involves participants attempting to ride a unicycle over obstacles without any part of the rider touching the ground.
The obstacles traversed can be set up specifically for the purpose of unicycle trials, but are often walls, railings, ledges and other "street furniture" found in an urban environment. The sport is derived from (or at least inspired by) bike trials and motorcycle trials.
Obstacles are traversed using various moves. Hopping is achieved by suddenly forcing the unicycle
Unicycle
A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a frame with a saddle, and has a pedal-driven direct drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performers, in festivals, and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years, unicycles have also been used in mountain unicycling, an activity similar to mountain biking or