We call it "floating wax", which is mostly used in bars, western restaurants, cafes and wedding festivals. There is no special uniform terminology.

Have a plenty of aluminum shell base, generally white, can also float, but mostly used for candlesticks and candle cups.

Some have no aluminum shell, and they are usually colored, some are spherical and some are flat, which is the most common container for holding water.

There are many names:

Floating wax

Water floating wax

Floating wax

Atmospheric floating wax