Originally, bongs were made from large hollow bamboo stalks. The intent is place enough pot for a full hit in the bowl, , smoke it until it burns out and the ashes go down the bowl into the water. That way there is a minimum of smoke going into the atmosphere, and more efficient delivery into the lungs
A hookah is a type of water pipe from the middle east or north Africa. It was not originally intended for smoking cannabis. It usually has several hoses connected through the water to the bowl, so several smokers can share whatever is being smoked. Sometimes a hookah is called a hubbly-bubbly
All bongs are water pipes, not all water pipes are bongs.
All hookahs are water pipes, not all water pipes are hookahs.
Hookahs are not bongs, nor are bongs hookahs.
(I experienced my first bong in 1968, my first hookah in 1971)