What exactly is the difference between soup and bisque?

Soup, the generic) is generaly slurpy and eaten w. a spoon or drunk from a cup.. Bisque is soup and has things in it like lobster, if you are lucky.

bisque is a thick, rich soup that consists of pureed seafood and cream.

so all bisques have seafood?

Usually, but there are tomato and mushroom bisques as well. Possibly corn? Most of the main substance is pureed but there are often chunks of seafood or veggies floating around. Like a stew eaten w. a spoon and very very tasty. One can boil and puree a potatoe or two in order to avoid the cream.

Bisque is a thick soup. Its orgin is French. It does not have to have seafood or cream in it.Tradionally bisque was made from shellfish but has evolved to be made from vegetables like mushroom bisque. In south Louisiana we make a crawfish bisque which has no creamin it. It is a thick brown soup with crawfish tails and stuffed crawfish heads in it.

Originally, bisque was made from fish stock and thickened with corn starch and/or cream.
Mostly they are crab, lobster or shrimp bisques. (By the way, the seafood should not be pureed. I like big chunks of crab or lobster in mine). Nowadays bisque can be any thick, creamy soup, for example celery bisque or tomato bisque.

Difference? Cost! lol