A fountain is an ornamental structure with flowing or projected water, which is neither inside, on top of, or built into any other structure. It is distinguished from a simple water jet, which leaves barely any visible structure when turned off.

The ornamental construction has an independent position outside other structures. Its physical form remains visible as part of the display even when water is not flowing.

A water jet leaves little visible structure when switched off. The fountain combines moving water with a freestanding ornamental construction.