A jet ski is a personal watercraft (PWC) that is propelled by a jet of water. It's designed for recreational use on water, similar to how motorcycles are used on land.Here are some key characteristics of jet skis:

-Propulsion: They use an internal impeller that draws in water and then expels it at high pressure, creating thrust. This makes them relatively safe as there's no external propeller.

-Activities: They are commonly used for recreational riding, touring, towing water-skiers or tubers, and even for some competitive sports. 

In essence, a jet ski is a fun and exhilarating way to enjoy being on the water!