The difference between sole and flounder is that the best quality sole come from deep waters around Europe, whereas flounder rarely venture into the depths. Sole are edible flatfish in the flounder family, and both are sea fishes.
The most heavily fished type of flounder is the European flounder, which reaches a maximum length of 20 inches. The wildly popular Dover sole also grows up to 20 inches long, but other species are smaller. For example, sand soles only grow up to 14 inches, and the maximum length of the ceteau sole is a mere 10 inches.
Flounder is Australia's largest and most profitable seafood export, while European waters also have large flounder populations. Many species of sole and flounder have culinary applications, and their similar texture and flavor renders them interchangeable. These fish feature prominently in French cuisine, and Scandinavians frequently smoke and dry them. Sole and flounder are effective substitutes for turbot, brill, dab and plaice.
Most species of flounder and sole have both eyes on their right side. Newborn flounder have eyes on both sides, but within days, the left eye migrates to the right side. This side is a dark, variegated brownish-green. The left side, also called the blind side, is white.