What's the difference between jacuzzi, hot tub and in-bath whirlpools when looking at hotel room amenities?

When I look at different amenities for hotel rooms, some list having in-bath whirlpools, others will have hot tubs or jacuzzis. What is the difference between all of these?

Usually an in-bath whirlpool is just a "big" tub with jets to force the water around. Hot tubs and Jacuzzis are the same thing, usually always filled with water and treated just like a swimming pool and of course, "Hot"! Jacuzzi is actually a brand of hot tubs!!

in bath are in your room private

hot tubs are common rooms shared

some suites have jacuzzis all of their own

Jacuzzi is just a brand. A spa is one that you don't drian after you use it and are found outside a hotel or home it also fits more people. A whirlpool bath is one that you would drain right after you use it. They all have a heater though its option and a blower.

hot tubs-flat, few jets (I have one)

In-bath whirlpools- same things as hot tubs

Jacuzzi- comfy seating, lots of jets, tempature control.

I prefer Jacuzzis.