A “Whirlpool”, the way the word is commonly used, refers to any spa or hot tub’s circular “water action”. Remember, a “Jacuzzi” is not a generic name for spas. Jacuzzi is a company that makes “whirlpool baths” and spas. Any spa or hot tub will provide you with this “whirlpool action” of the water.
A hot tub is a large tub or small pool full of heated water used for hydrotherapy, relaxation or pleasure. Some have powerful jets for massage purposes. Hot tubs are sometimes also known as SPAS.