Chowder is a thick, rich and creamy soup or stew made of made of sea-food, fish or vegetables. The most well known is clam chowder. Others are seafood chowder, corn chowder, fish chowder, chicken chowder
The soup is prepared with milk or cream and thickened with roux. Other ingredients may include potatoes, onion, celery, carrots corn and bacon.
The soup may be accompanied with oyster crackers or saltines. The crackers may also be sprinkled on top like croutons. (wiki)
The name comes form French chaudière, which means a cauldron in which fishermen made their stews fresh from the sea. (Food Lover’s Companion)